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TREATISE 



ON 



ANATOMY, 
PHYSIOLOGY, AND HYGIENE 



DESIGNED FOR 



COLLEGES, ACADEMIES, AND FAMILIES: 

BY 

CALVIN CUTTER, M. D. 



WITH ONE HUNDRED AND FIFTY ENGRAVINGS. 



STEREOTYPE EDITION. 

BOSTON: 
BENJAMIN B. MUSSEY AND CO. 

NEW YORK: CLARK, AUSTIN, AND CO. BALTIMORE: CUSHING AND 

BROTHER. CHARLESTON, S. C. : M'CARTER AND ALLEN. 

LOUISVILLE, KY. : MORTON AND GRLSWOLD. 

CINCINNATI: GEORGE COXE AND CO. 

DETROIT : A. M'FARREN AND CO. 

1849. 



PREFACE. 



Agesilatjs, king of Sparta, when asked what things boys 
should learn, replied, "Those which they will practise when 
they become men." As health requires the observance of 
the laws inherent to the different organs of the human system, 
so not only boys, but girls, should acquire a knowledge of the 
laws of their organization. If sound morality depends upon 
the inculcation of correct principles in youth, equally so does 
a sound physical system depend on a correct physical edu- 
cation during the same period of life. If the teacher and 
parents who are deficient in moral feelings and sentiments, 
are unfit to communicate to children and youth those high 
moral principles demanded by the nature of man, so are they 
equally incompetent directors of the physical training of the 
youthful system, if ignorant of the organic laws and the phys- 
iological conditions upon which health and disease depend. 

For these reasons, the study of the structure of the human 
system, and the laws of the different organs, are subjects of 
interest to all, — the young and the old, the learned and tlje 
unlearned, the rich and the poor. Every scholar, and particu- 
larly every young miss, after acquiring a knowledge of the 
primary branches, — as spelling, reading, writing, and arith- 
metic, — should learn the structure of the human system, and 
1* 



b PREFACE. 

the conditions upon which health and disease depend, as this 
knowledge will be required in practice in after life. 

" It is somewhat unaccountable," says Dr. Dick, " and not 
a little inconsistent, that while we direct the young to look 
abroad over the surface of the earth, and survey its moun- 
tains, rivers, seas, and continents, and guide their views to 
the regions of the firmament, where they may contemplate 
the moons of Jupiter, the rings of Saturn, and thousands of 
luminaries placed at immeasurable distances, * * that we 
should never teach them to look into themselves ; to consider 
their own corporeal structures, the numerous parts of which 
they are composed, the admirable functions they perform, the 
wisdom and goodness displayed in their mechanism, and the 
lessons of practical instruction which may be derived from 
such contemplations. 1 ' 

Again he says, "One great practical end which should 
always be kept in view in the study of physiology, is the 
invigoration and improvement of the corporeal powers and 
functions, the preservation of health, and the prevention of 
disease." 

The design of the following pages is, to diffuse in the 
community, especially among the youth, a knowledge of 
Human Anatomy, Physiology, and Hygiene. To make 
the work clear and practical, the following method has 
been adopted : — 

1st. The structure of the different organs of the system 
has been described in a clear and concise manner. To 
render this description more intelligible, one hundred and 
fifty engravings have been introduced, to show the situation 
of the various organs. Hence the work may be regarded 
as an elementary treatise on anatomy. 



PREFACE. 7 

2d. The functions, or uses of the several parts have been 
briefly and plainly detailed ; making a primary treatise on 
human physiology. 

3d. To make a knowledge of the structure and functions 
of the different organs practical, the laws of the several 
parts, and the conditions on which health depends, have 
been clearly and succinctly explained. Hence it may be 
called a treatise on the principles of hygiene, or health. 

To render this department more complete, there has been 
added the appropriate treatment for burns, wounds, hemor- 
rhage from divided arteries, the management of persons 
asphyxiated from drowning, carbonic acid, or strangling, 
directions for nurses, watchers, and the removal of disease, 
together with an Appendix, containing antidotes for poisons, 
so that persons may know what should he done, and what 
should not he done, until a surgeon or physician can be 
called. 

In attempting to effect this in a brief elementary treatise 
designed for schools and families, it has not been deemed 
necessary to use vulgar phrases for the purpose of being 
understood. The appropriate scientific term should be applied 
to each organ. No more effort is required to learn the mean- 
ing of a proper, than an improper term. For example : a 
child will pronounce the word as readily, and obtain as 
correct an idea, if you say lungs, as if you used the word 
lights. A little effort on the part of teachers and parents, 
would diminish the number of vulgar terms and phrases, and, 
consequently, improve the language of our country. To 
obviate all objections to the use of proper scientific terms, a 
Glossary has been appended to the work. 



8 PREFACE. 

The author makes no pretensions to new discoveries in 
physiological science. In preparing the anatomical depart- 
ment, the able treatises of Wilson, Cruveilhier, and others 
have been freely consulted. In the physiological part, the 
splendid works of Carpenter, Dunglison, Liebig, and others 
have been perused. In the department of hygiene many 
valuable hints have been obtained from the meritorious 
works of Combe, Rivers, and others. 

We are under obligations to R. D. Mussey, M. D., formerly 
Professor of Anatomy and Surgery, Dartmouth College, 
N. H., now Professor of Surgery in the Ohio Medical Col- 
lege ; to J. E. M'Girr, A. M., M. D., Professor of Anatomy, 
Physiology, and Chemistry, St. Mary's University, 111. ; to 
F. Merrick, M. D., Professor of Anatomy, in Starling Medical 
College, O. ; to Rev. E. Hitchcock, D. D., President of 
Amherst College, Mass., who examined the revised edition of 
this work, and whose valuable suggestions rendered important 
aid in preparing the manuscript for the present stereotype 
edition. 

We return our acknowledgments for the aid afforded by the 
Principals of the several Academies and Normal Schools, who 
formed classes in their institutions, and examined the revised 
edition as their pupils progressed, thus giving the work the 
best possible test trial, namely, the recitation-room. 

To the examination of an intelligent public, the work is 
respectfully submitted by 

CALVIN CUTTER. 

Boston, January 1, 1849. 



TO TEACHERS AND PARENTS. 



As the work is divided into chapters, the subjects of 
which are complete in themselves, the pupil may com- 
mence the study of the structure, use, and laws of the 
several parts of which the human system is composed, 
by selecting such chapters as fancy or utility may dic- 
tate, without reference to their present arrangement, 
— as well commence with the chapter on the digestive 
organs as on the bones. 

The acquisition of a correct pronunciation of the 
technical words is of great importance, both in recita- 
tion and in conversation. In this work, the technical 
words interspersed with the text, have been divided 
into syllables, and the accented syllables designated. 
An ample Glossary of technical terms has also been 
appended to the work, to which reference should be 
made. 

It is recommended that the subject be examined in 
the form of topics. The questions in Italics are de- 
signed for this method of recitation. The teacher 
may call on a pupil of the class to describe the anat- 
omy of an organ from an anatomical outline plate ; 
afterwards call upon another to give the physiology 
of the part, while a third may state the hygiene, after 



10 TO TEACHERS AND PARENTS. 

which, the questions at the bottom of the page may- 
be asked promiscuously, and thus the detailed knowl- 
edge of the subject possessed by the pupils will be 
tested. 

At the close of the chapters upon the Hygiene of 
the several portions of the system, it is advised that 
the instructor give a lecture reviewing the anatomy, 
physiology, and hygiene, of the topic last considered. 
This may be followed by a general examination of 
the class upon the same subject. By this course a 
clear and definite knowledge of the mutual relation of 
the Anatomy, Physiology, and Hygiene, of different 
parts of the human body, will be presented. 

We also suggest the utility of the pupils' giving 
analogous illustrations, examples, and observations, 
where these are interspersed in the different chap- 
ters, not only to induce inventive thought, but to 
discipline the mind. 

To parents and others we beg leave to say, that 
about two thirds of the present work is devoted to a 
concise and practical description of the uses of the 
important organs of the human body, and to show 
how such information may be usefully applied, both 
in the preservation of health, and the improvement of 
physical education. To this have been added direc- 
tions for the treatment of those accidents which are 
daily occurring in the community, making it a treatise 
proper and profitable for the family library, as well 
as the school-room. 



CONTENTS 



Chapter. Page. 

1. General Remarks, 13 

2. Structure of Man, 17 

3. Chemistry of the Human Body, 25 

4. Anatomy of the Bones, 29 

5. Anatomy of the Bones, continued, 39 

6. Physiology of the Bones, 48 

7. Hygiene of the Bones, 53 

8. Anatomy of the Muscles, 64 

9. Physiology of the Muscles, 76 

10. Hygiene of the Muscles, 85 

11. Hygiene of the Muscles, continued, 96 

12. Anatomy of the Teeth, 105 

12. Physiology of the Teeth, 109 

12. Hygiene of the Teeth, 110 

13. Anatomy of the Digestive Organs, 113 

14. Physiology of the Digestive Organs, 124 

15. Hygiene of the Digestive Organs, 129 

16. Hygiene of the Digestive Organs, continued, 142 

17. Anatomy of the Circulatory Organs,. 154 

18. Physiology of the Circulatory Organs, 164 

19. Hygiene of the Circulatory Organs, 172 

20. Anatomy of the Lymphatic Vessels 181 

20. Physiology of the Lymphatic Vessels, 183 

20. Hygiene of the Lymphatic Vessels, 188 

21. Anatomy of the Secretory Organs, 192 

21. Physiology of the Secretory Organs, 193 

21. Hygiene of the Secretory Organs, 197 

22. Nutrition, 200 

22. Hygiene of Nutrition, 205 

23. Anatomy of the Respiratory Organs, 209 



12 CONTENTS. 

Chapter. Page. 

24. Physiology of the Respiratory Organs, 217 

25. Hygiene op the Respiratory Organs, 228 

26. Hygiene of the Respiratory Organs, continued 239 

27. Animal Heat, 252 

28. Hygiene of Animal Heat, 261 

29. Anatomy of the Vocal Organs, 268 

29. Physiology of the Vocal Organs, 272 

30. Hygiene of the Vocal Organs, 274 

31. Anatomy of the Skin 282 

32. Physiology of the Skin, , 293 

33. Hygiene of the Skin, 301 

34. Hygiene of the Skin, continued, 311 

35. Appendages of the Skin, 322 

36. Anatomy of the Nervous System 327 

37. Anatomy of the Nervous System, continued, 340 

38. Physiology of the Nervous System, 346 

39. Hygiene of the Nervous System, 358 

40. Hygiene of the Nervous System, continued, 368 

41. The Sense of Touch, 378 

42. Anatomy of the Organs of Taste, 384 

42. Physiology of the Organs of Taste, 386 

43. Anatomy of the Organs of Smell, 389 

43. Physiology of the Organs of Smell, 391 

44. Anatomy of the Organs of Vision, 394 

45. Physiology of the Organs of Vision, 404 

45. Hygiene of the Organs of Vision, 410 

46. Anatomy of the Organs of Hearing, 414 

47. Physiology of the Organs of Hearing, 420 

47. Hygiene of the Organs of Hearing 422 

48. Means of preserving the Health, 425 

49. Directions for Nurses, 432 



APPENDIX 438 

GLOSSARY, 443 

INDEX, 455 



ANATOMY, ETC. 



CHAPTER I. 

GENERAL REMARKS. 

1. Anatomy is the term applied to the description of the 
mechanism, or structure, of the parts of the system. It prop- 
erly signifies the art of dissecting, or artificially separating 
the different parts of the animal body. 

2. Physiology is the science of the properties and func- 
tions of animals and plants. Animal physiology is divided 
into Human and Comparative. 

3. Human Physiology treats of the laws by which the 
various functions in man are performed. 

4. Comparative Physiology treats of the functions of the 
inferior animals. 

5. Vegetable Physiology treats exclusively of plants. 

6. Hygiene is the art of preserving health, or that depart- 
ment of medicine which treats of the preservation of health. 

7. The kingdom of nature is divided into organic and in- 
organic bodies. Organic bodies possess organs, on whose 
action depend their growth and perfection. This division 
includes animals and plants. Inorganic bodies are devoid of 

1. What is anatomy ? 2. What is physiology ? How is animal phys- 
iology divided? 3. Of what does human physiology treat? 4. Com- 
parative physiology ? 5. Vegetable physiology ? 6. What is hygiene ? 
7. Define organic bodies. Define inorganic bodies. 

2 



14 ANATOMY, PHYSIOLOGY, AND HYGIENE. 

organs, or instruments of life. In this division are classed 
the earths, metals v and other minerals. 

8. In general, organic matter differs so materially from 
inorganic, that the one can readily be distinguished from 
the other. In the organic world, the parts are mutually 
dependent on each other for support. Break the tiny stem of 
a rose, and it soon withers ; or girdle the bark of the forest 
tree, and it dies, because it cannot receive support from the 
ascending sap. So in man ; amputate an arm, and its vitality 
ceases, for the vessels communicating with it have been 
severed. But, in inorganized bodies, the results are different. 
Break off a piece of flint, and it is exempt from those in- 
ternal changes and effects which impair and finally destroy 
organic structure and arrangement. 

9. " Organized bodies always present a combination of 
both solids and fluids ; — of solids, differing in character and 
properties, arranged into organs, and these endowed with 
functional powers, and so associated as to form of the whole 
a single system; — and of fluids, contained in these organs, 
and holding such relation to the solids that the existence, 
nature, and properties of both mutually and necessarily de- 
pend on each other. 

10. " Every inorganic body consists wholly either of the 
solid, liquid, or gaseous, form of matter ; and all its parts are 
alike in structure and properties, and may exist as well when 
separated, into portions or broken into fragments, as when 
united in a single volume or mass. But whether solid, liquid, 
or gaseous, whether composed of one or more of the chemical 
elements, the aggregations and arrangements of the atoms 
of matter, in every substance, take place according to fixed, 
constitutional laws, and in a regular and determinate manner ; 

8. Show the difference between organic and inorganic bodies. 9. "What 
do organized bodies always present ? 10. In what forms do inorganic 
bodies exist ? What distinctive difference between inorganic and organic 
bodies ? 



GENERAL REMARKS. 15 

so that the intimate structure of each form of matter is always 
in accordance with its own nature.' 1 

11. Organized bodies increase in size by a process called 
nutrition, which consists in imbibing substances and convert- 
ing them to their own nature, by means of internal organs. 
They have, within a certain range, their specific proportions, 
shape, and size, by which they are not only distinguished 
from inorganic bodies, but specifically from each other. In- 
organic bodies, on the contrary, increase in size, or change 
in shape, by the simple accretion of matter to their surfaces. 
Thus it will be seen that organized bodies augment in bulk 
from within, and inorganized bodies from without. 

12. Though animals and vegetables derive their origin from 
preexisting bodies of the same kind, and possess the faculties 
of nutrition and reproduction, yet the animal kingdom is as 
distinct from the vegetable as the latter is from the mineral 
kingdom. The fundamental endowments which distinguish 
animals from vegetables are sensation and voluntary motion. 
The latter are destitute of these qualities. Another character- 
istic of animals is the predominance of the fluid over the 
solid parts. This causes them to decompose sooner than 
vegetables. 

13. The differences between the animal and vegetable 
kingdoms are, in general, sufficiently obvious ; but, in some 
few instances, their distinguishing characteristics are not so 
evident. In the lowest order of animals, as the sponge, 
coral, &c, we find them to be as firmly attached to the soil 
as most vegetables ; while, on the other hand, some vegetables 
are never attached to the soil, but float in the water, as many 
kinds of sea-weed. 

14. All organized bodies have a limited period of life, 

11. How do organized bodies increase in bulk ? Inorganic ? 12. What 
are the fundamental endowments which distinguish animals from vegeta- 
bles ? What is another characteristic of animals ? 13. What is said of 
the differences between the animal and vegetable kingdoms ? 14. What 
is said of the life of organized bodies ? 



16 ANATOMY, PHYSIOLOGY, AND HYGIENE. 

which varies with every species. In some the period is 
limited to a single day, — in many plants, to a single sum- 
mer ; while some animals live more than a century, as the 
elephant ; and some trees, as a species of oak, and the olive, 
are supposed to live a thousand years. The duration of life 
is shortened by disease, and rarely occurs to vegetables or 
animals in their native condition, while man is so subject to it 
that his average length of life is less than half its natural 
period. 

15. Disease, however, is under the control of fixed laws, 
which we are capable of understanding and obeying. Nor 
do diseases come by chance ; they are penalties for violating 
physical laws. If we carelessly cut or bruise our flesh, pain 
and soreness follow, to induce us to be more careful in the 
future ; or, if we take improper food into the stomach, we 
are warned, perhaps immediately by a friendly pain, that we 
have violated an organic law. 

16. Sometimes, however, the penalty does not directly fol- 
low the sin, and it requires great physiological knowledge to 
be able to trace the effect to its true cause. If we possess 
good constitutions, we are responsible for most of our sick- 
ness ; and bad constitutions, or hereditary diseases, are but 
the results of the same great law, — the iniquities of the 
parents being visited on the children. In this view of the 
subject, how important is the study of physiology and hygiene ! 
For how can we expect to obey laws which we do not under- 
stand ? 

15. "What is said of disease ? 16. Why is the study of physiology and 
hygiene important ? 



STRUCTURE OF MAN. 17 



CHAPTER II. 

STRUCTURE OF MAN. 

17. In the structure of the human body, there is a union 
of fluids and solids. These are essentially the same, for the 
one is readily changed into the other. There is no fluid that 
does not contain solid matter in solution, and no solid matter 
that is destitute of fluid. 

18. In different individuals, and at different periods of life, 
the proportion of fluids and solids varies. In youth, the fluids 
are more abundant than in advanced life. For this reason, 
the limbs in childhood are soft and round, while in old age 
they assume a hard and wrinkled appearance. 

19. The fluids not only contain the materials from which 
every part of the body is formed, but they are the medium 
for conveying the waste, decayed particles of matter from the 
system. They have various names, according to their nature 
and function ; as, the blood, and the bile. 

20. The solids are formed from the fluids, and consequent- 
ly they are reduced, by chemical analysis, to the same ultimate 
elements. The particles of matter in solids are arranged 
either in fibres (threads) or lam'in-cB (plates.) These are so 
disposed as to form small spaces, called cells. 

21. The parts of the body are arranged into Fil'a-ments, 
Fi'bres, Tis'sues, Or'gans, Ap-pa-ra'tas-es, and Sys'tems. 



17. "What substances enter into the structure of the human body ? Are 
they essentially the same ? 18. What is said of these substances at differ- 
ent periods of life ? 19. What offices do the fluids of the system perform? 
20. What is said of the solids ? How are the particles of matter ar- 
ranged in solids ? 21. Give an arrangement of the parts of the body. 
2* 



18 



ANATOMY, PHYSIOLOGY, AND HYGIENE. 



22. A filament is composed of minute particles of mat- 
ter, arranged in a row. 

23. A fibre is composed of several filaments united, each 
of which is enclosed in a sheath. 

24. A tissue is the interlacement or union of fibres ; as, 
the cellular tissue. 

25. An organ is composed of tissues so arranged as to 
form an instrument designed for action. The action of an 
organ is called its function, or use. 

Example. The liver is an organ, and the secretion of the 
bile from the blood is one of its functions.* 

26. An apparatus is an assemblage of organs designed 
to produce certain results. 

Example. The digestive apparatus consists of the teeth, 
stomach, liver, &c, all of which aid in the digestion of food. 

Fig. 2. 
1 3 




Fig. 2. 1. A fibre enclosed in its sheath. 2. A filament very highly magnified. 
3. A fibre greatly magnified. 

27. The term system is applied to an assemblage of 
organs arranged according to some plan, or method ; as the 
nervous system, the respiratory system. 



* "Where examples and observations are given or experiments 
suggested, let the pupil mention other analogous ones. 

22. Define a filament. 23. Define a fibre. 24. Define a tissue. 25. De- 
fine an organ. What is the action of an organ called ? Give examples. 
Mention other examples. 26. What is an apparatus ? Give an example. 
27. How is the term system applied ? 



STRUCTURE OF MAN. 19 

28. A membrane is the simplest form of organized animal 
substance. It is flexible, and formed of fibres interwoven like 
net-work ; as, the mucous membrane. 

29. However various all organs may appear in their struc- 
ture and composition, it is now supposed that they can be 
reduced to five simple membranes, namely, the Cel'lu-lar, 
Mus'cu-lar, Ner'vous, Mem'bra-nous, and Os'se-ous. 

30. The cellular membrane extends throughout all parts 
of the body. It is composed of small fibres, of every variety 
of shape and size, running in every possible direction, form- 
ing a net-like arrangement. In some situations, these fibres 
are narrow, loose, and comparatively distant. In others, they 
are broad and close, so as to form partial cells, which com- 
municate with each other. These cells are prevented from 
adhering by a fluid secreted from the blood. 

Fix. 3. 




Fig. 3. A representation of a single film of the cellular membrane raised and 
slightly distended. 

Observations. 1st. When this fluid becomes too great in 
quantity, in consequence of disease, the patient labors under 
general dropsy. The swelling of the feet when standing, and 
their return to a proper shape during the night, so often 
noticed in feeble persons, furnish a striking proof both of the 

28. "What is a membrane ? 29. "What is said respecting the structure 
and composition of the various organs ? Name the primary membranes. 
30. How is the cellular membrane formed? How are the cells prevented 
from adhering ? Give observation 1st, relative to the cellular membrane. 



20 ANATOMY, PHYSIOLOGY, AND HYGIENE. 

existence and peculiarity of this membrane, which allows the 
fluid to flow from cell to cell, until it settles in the lower 
extremities. 

2d. The free communication between the cells is still 
more remarkable in regard to air. Sometimes, when an 
accidental opening has been made from the air-cells of the 
lungs into the contiguous cellular tissue, the air in respiration 
has penetrated every part until the whole body is so inflated 
as to occasion suffocation. Butchers often avail themselves 
of the knowledge of this fact, and inflate their meat to give it 
a fat appearance. 

31. " Although this tissue enters into the composition of all 
organs, it never loses its own structure, nor participates in the 
functions of the organ of which it forms a part. Though 
present in the nerves, it does not share in their sensibility ; 
and though it accompanies every muscle and every muscular 
fibre, it does not partake of the irritability which belongs to 
these organs." 

32. The varieties of membrane, formed from the cellular, 
are, the Ad'i-pose, Se'rous, Mu'cous, Derm'oid, Fi'brous, 
Car-ti-lag'in-ous, and the Os'se-ous. 

33. The adipose membrane, or tissue, is so arranged as to 
form distinct bags, or cells. These contain a substance called 
fat. This tissue is principally found beneath the skin, abdomi- 
nal muscles, and around the heart and kidneys ; while none 
is found in the brain, eye, ear, nose, a*«id several other organs. 

Observation. In those individuals who are corpulent, there 
is, in many instances, a great deposit of this substance. This 
tissue accumulates more readily than others when a person 
becomes gross, and is earliest removed when the system 
emaciates, in acute or chronic diseases. Some of the masses, 



Give observation 2d. 31. What is said of the identity of this membrane ? 
32. Name the varieties of membrane formed from the cellular. 33. De- 
scribe the adipose membrane. Where does this tissue principally exist ? 
Give observation in regard to the adipose tissue. 



STRUCTURE OF MAN. 



21 



called pel'i-tongs, become, in some instances, enlarged. These 
enlargements are called adipose, or fatty tumors. 

34. The serous membrane lines all the closed, or sac-like 
cavities of the body ; as, the chest, joints, and abdomen. It 
not only lines these cavities, but is reflected, and invests the 
organs contained in them. The liver and the lungs are thus 
invested. This membrane is of a whitish color, and smooth 
on its free surfaces. These surfaces are kept moist, and pre- 
vented from adhering by a se'rous fluid, which is separated 
from the blood. The use of this membrane is to separate 
organs, and also to facilitate the movement of one part upon 
another, by means of its moist, polished surfaces. 




Fig, 4. 1, A portion of the adipose membrane 2, 2, 2, Minute bags containing fat. 
3, A cluster of these bags, separated and suspended. 

35. The mucous membrane differs from the serous by its 
lining all the cavities which communicate with the air. The 
nostrils, the mouth, and the stomach afford examples. The 
external surface of this membrane, or that which is exposed 
to the air, is soft, and bears some resemblance to the downy 

34. Where is the serous membrane found ? "What two offices does it per- 
form ? Give its structure. What is the use of this membrane ? 35. How 
does the mucous differ from the serous membrane ? What is the appear- 
ance of the external surface of this membrane ? 



22 ANATOMY, PHYSIOLOGY, AND HYGIENE. 

rind of a peach. It is covered by a viscid fluid, called mu'cus; 
this is secreted by small glands, which are situated in the 
substance of the membrane. The use of this membrane is 
to protect the inner surfaces of the cavities which it lines. 

Observation. A remarkable sympathy exists between the 
remote parts of the mucous membrane. Thus the condition 
of the stomach may be ascertained by an examination of the 
tongue. 

36. The dermoid membrane covers the outside of the 
body. It is called the cu'tis, (skin.) This membrane is con- 
tinuous with the mucous at the various orifices of the body, 
and in these situations, from the similarity of their structure, 
it is difficult to distinguish between them. 

Observations. 1st. In consequence of the continuity and 
similarity of structure, there is close sympathy between the 
mucous and dermoid membranes. If the functions of the 
skin are disturbed, as by a chill, it will frequently cause a 
catarrh, (cold,) or diarrhoea. Again, in consequence of this 
intimate sympathy, these complaints can be relieved by excit- 
ing a free action in the vessels of the skin. 

2d. It is no uncommon occurrence that diseased or irri- 
tated conditions of the mucous membrane of the stomach or 
intestines produce diseases or irritations of the skin, as is 
seen in the rashes attendant on dyspepsia, and eating certain 
species of fish. These eruptions of the skin can be relieved 
by removing the diseased condition of the stomach. 

37. The fibrous tissue consists of longitudinal, parallel 
fibres, which are closely united. These fibres, in some situ- 
ations, form a thin, dense, strong membrane, like that which 



What is the use of this membrane ? "Why does the tongue indicate the 
state of the stomach ? 38. Describe the dermoid membrane. What is said 
of the sympathy between the functions of the skin and mucous membrane ? 
Give another instance of the sympathy between these membranes. 37. Of 
what does the fibrous tissue consist ? How do these appear in some situ- 
ations ? 



STRUCTURE OF MAN. 23 

lines the internal surface of the skull, or invests the external 
surface of the bones. In other instances, they form strong, 
inelastic bands, called lig'a-ments, which bind one bone to an- 
other. This tissue also forms ten'dons, (white cords,) by which 
the muscles are attached to the bones. 

Observation. In the disease called rheumatism, the fibrous 
tissue is the part principally affected ; hence the joints, where 
this membrane is most abundant, suffer most from this affec- 
tion. 

38. The cartilaginous tissue is firm, smooth, and high- 
ly elastic. Except bone, it is the hardest part of the animal 
frame. It tips the ends of the bones that concur in forming 
a joint. Its use is to facilitate the motion of the joints by its 
smooth surface, while its elastic character diminishes the shock 
that would otherwise be experienced if this membrane were 
inelastic. 

Fig. 5. 

1 




Fig. 5. A section of the femur, (thigh-bone.) 1, 1, The extremities, showing a 
thin phite of compact texture, which covers small cells, that diminish in size, but 
increase in' number, as they approach the articulation. 2, 2, The wails of the shaft, 
which are very firm and solid. 3, The cavity that contains the marrow. 

39. The osseous tissue, in composition and arrangement 
of matter, varies at different periods of life, and in different 
bones. In some instances, the bony matter is disposed in 
plates, while in other instances, the arrangement is cylindrical. 
Sometimes, the bony matter is dense and compact ; again, it is 

How in others ? What tissue is generally affected in rheumatism ? 
38. Describe the cartilaginous tissue. What is its use ? 39. What is said 
of the osseous tissue ? How is the bony matter arranged in different parts 
of the animal frame ? 



24 ANATOMY, PHYSIOLOGY, AND HYGIENE. 

spongy, or porous. In the centre of the long bones, a space 
is left which is filled with a fatty substance, called mar 1 row. 

Observation. Various opinions exist among physiologists in 
regard to the use of marrow. Some suppose it serves as a 
reservoir of nourishment, while others, that it keeps the bones 
from becoming dry and brittle. The latter opinion, however, 
has been called in question, as the bones of the aged man 
contain more marrow than those of the child, and they are 
likewise more brittle. 

40. The muscular membrane is composed of many fila- 
ments, that unite to form fibres, each of which is enclosed in 
a delicate layer of cellular membrane. Bundles of these fibres 
constitute a muscle* 

Observation. A piece of boiled beef will clearly illustrate 
the arrangement of muscular fibre. 

41. The nervous tissue consists of soft, pulpy matter, 
enclosed in a sheath, called neu-ri-lem'a. This tissue consists 
of two substances. The one, of a pulpy character and gray 
color, is called cin-e-ri'tions, (ash-colored.) The other, of a 
fibrous character and white, is named med'ul-la-ry, (marrow- 
like.) In every part of the nervous system both substances 
are united. 

"What is said of the use of marrow ? 40. Of what is the muscular tissue 
composed ? How may the arrangement of muscular fibre be illustrated ? 
41. Of what does the nervous tissue consist ? Describe the two substances 
that enter into the composition of the nervous tissue. 



CHEMISTRY OF THE HUMAN BODY. 25 

CHAPTER III. 

— - CHEMISTRY OF THE HUMAN BODY. 

42. The term ultimate elements is used in speaking of 
the chemical composition of the human body. 

43. The ultimate elements are divided into metallic and 
non-metallic substances. The metallic substances are Po- 
tas'si-um, So'di-um, Cal'ci-um, Mag-ne'si-um, A-lu'min-um, 
I'ron, Man'ga-nese, and Cop'per. The non-metallic sub- 
stances are Ox'y-gen, Hy'dro-gen, Car'bon, Ni'tro-gen, Si-W- 
ci-um, Phos'phor-us, Sul'phur, Chlo'rine, and a few others. 

44. Potash (potassium united with oxygen) is found in 
the blood, bile, perspiration, milk, &c. 

45. Soda (sodium combined with oxygen) exists in the 
muscles, and in the same fluids in which potash is found. 

46. Lime (calcium combined with oxygen) forms the prin- 
cipal ingredient of the bones. The lime in them is combined 
with phosphoric and carbonic acid. 

47. Magnesia (magnesium combined with oxygen) exists 
in the bones, brain, and in some of the animal fluids; as milk. 

48. Silex (silicium combined with oxygen) is contained in 
the hair and in some of the secretions. 

49. Iron forms the coloring principle of the red globules 
of the blood, and is found in every part of the system. 

Observation. As metallic or mineral substances enter into 
the ultimate elements of the body, the assertion that all min- 
erals are poisonous, however small the quantity, is untrue. 

42. "What term is used in speaking of the chemical composition of the 
human body ? 43. How are they divided ? Name the metallic substances. 
Name the non-metallic substances. 44. What is said of potash ? 45. Of 
soda ? 46. Of lime ? 47. Of magnesia ? 48. Of silex ? 49. What forms 
the coloring principle of the blood ? What is said of mineral substances ? 
3 



26 ANATOMY, PHYSIOLOGY, AND HYGIENE. 

50. Oxygen is contained in all the fluids and solids of the 
body. It is derived partly from the inspired air, and partly 
from the food and drink. This element is expelled from the 
system in the secretions and excretions. 

51. Hydrogen is found in all the fluids, and in some of the 
solids. It is most abundant in the impure, dark-colored blood 
of the system. The bile, fat, and oil contain this element. 
Hydrogen is derived from the food and drink, and is expelled 
from the system in the same manner as oxygen. 

Observation. This gas sometimes accumulates in the stom- 
ach, and causes pain. When combined with sulphur, it pro- 
duces fetid eructations. 

52. Carbon is an element in the oil, fat, albumen, fibrin, 
gelatin, bile, and mucus. This element likewise exists in the 
venous blood in the form of carbonic acid gas. Carbon is 
obtained from the food, and discharged from the system by 
the secretions and respiration. 

53. Nitrogen, or azote, is contained in all animal matter, 
but is most abundant in fibrin. 

Observation. The peculiar smell of animal matter when 
burning is owing to nitrogen. This element combined with 
hydrogen forms am-mo'ni-a, (hartshorn.) when animal matter 
is in a state of putrefaction. 

54. Phosphorus is contained in almost every part of the 
body, but more particularly in the bones. In general, it is 
found combined with oxygen, forming phosphoric acid. 

Observation. There are well-attested cases of the spon- 
taneous combustion of human bodies, particularly among 
inebriates. It is assumed by some that this is owing to the 
accumulation of phosphorus in the system. 

55. Sulphur exists in the bones, muscles, hair, and nails. 
It is expelled from the system by the skin and intestines. 

50. "What is said of oxygen ? 51. Of hydrogen ? Give observation. 
52. What is said of carbon ? 53. Of nitrogen ? How is ammonia formed ? 
54. "What is said of phosphorus ? Give observation. 55. "What is said of 
sulphur ? 



CHEMISTRY OF THE HUMAN BODY. 27 

56. Chlorine is found in the blood, gastric juice, milk, 
perspiration, and saliva. 

57. The term proximate elements is used in speaking of 
the organic composition of the human body. The proximate 
elements are mostly formed from a combination of oxygen, 
hydrogen, carbon, and azote. The most important com- 
pounds are Al-bu'men, Fi'brin, Gel'a-tin, Mu'cus, and Os'ma- 
zome. 

58. Albumen is found in the body, both in a fluid and solid 
form. It is an element of the skin, glands, hair, and nails, 
and forms the principal ingredient of the brain. Albumen is 
without color, taste, or smell, and it coagulates by heat, acids, 
and alcohol. 

Observation. The white of an egg is composed of albu- 
men, which can be coagulated or hardened by alcohol. As 
albumen enters so largely into the composition of the brain, is 
not the impaired intellect and moral degradation of the inebri- 
ate attributable to the effect of alcohol in hardening the albu- 
men of this organ ? 

59. Fibrin exists abundantly in the blood, chyle, and 
lymph. It constitutes the basis of the muscles. Fibrin is 
of a whitish color, inodorous, and insoluble in cold water. It 
differs from albumen by possessing the property of coagu- 
lating at all temperatures. 

Observation. Fibrin may be obtained by washing the thick 
part of blood with cold water ; by this process, the red glob- 
ules, or coloring matter, are separated from this element. 

60. Gelatin is found in nearly all the solids, but it is not 
known to exist in any of the fluids. It forms the basis of the 
cellular tissue, and exists largely in the skin, bones, ligaments, 
and cartilages. 

56. Of chlorine ? 57- What term is used in speaking of the organic 
composition of the human body ? From what are the proximate elements 
mostly formed ? Name the most important compounds. 58. What is said 
of albumen. Give observation relative to this element. 59. Of fibrin ? 
How does albumen differ from fibrin ? How can fibrin be obtained ? 
60. What is said of gelatin ? 



a« ANATOMY, PHYSIOLOGY, AND HYGIENE. 

Observation. Gelatin is known from other organic principles 
by its dissolving in warm water, and forming " jelly." When 
dry, it forms the hard, brittle substance, called glue. Isin- 
glass, which is used in the various mechanical arts, is obtained 
from the sounds of the sturgeon. 

61. Mucus is a viscid fluid secreted- by the mucous mem- 
brane, which it serves to moisten and defend. It is found in 
the cuticle, nails, and hair. When dry, it is insoluble in 
water. 

62. Osmazome is a substance of an aromatic flavor. It is 
of a yellowish-brown color, and is soluble both in water 
and alcohol, but does not form a jelly by concentration. 
It is found in all the fluids, and in some of the solids ; as 
the brain. 

Observation. The characteristic odor and taste of soup are 
owing to osmazome. 

63. There are several acids found in the human system ; 
as the A-ce'tic, Ben-zo'ic, Ox-al'ic, Uric, and some other sub- 
stances, but not of sufficient importance to require a particu- 
lar description. 

How is it known from other organic principles ? 61. What is said of 
mucus ? 62. Of osmazome ? To what are the taste and odor of soup 
owing ? 63. What acids are found in the system ? 



4NAT0MY OF THE BONES. 29 

CHAPTER IV. 

THE BONES. 

64. The bones are firm and hard, and of a dull white 
color. In all the higher orders of animals, among which is 
man, they are in the interior of the body, while in lobsters, 
crabs, &c, they are on the outside, forming a case which 
protects the more delicate parts from injury. 

65. In the mechanism of man, the variety of movements 
he is called to perform requires a correspondent variety of 
component parts, and the different bones of the system are 
so admirably adapted to each other, that they admit of nu- 
merous and varied motions. 

66. When the bones composing the skeleton are united by 
natural ligaments, they form what is called a natural skeleton ; 
when united by wires, what is termed an artificial skeleton. 

67. The elevations, or protuberances, of the bones are 
called proc'es-ses, and are, generally, the points of attach- 
ment for the muscles and ligaments. 



ANATOMY OF THE BONES. 

68. The bones are composed of both animal and earthy 
matter. The earthy portion of the bones gives them solidity 
and strength, while the animal part endows them with vitality. 

64. What is said of the bones ? 65. Is there an adaptation of the bones 
of the system to the offices they are required to perform ? 66. What is a 
natural skeleton ? What an artificial ? 67- What part of the bones are 
called processes ? 68 — 73. Give the structure of the bones. 68. Of what are 
the bones composed ? What are the different uses of the component parts 
of the bones ? 

3 * 



30 ANATOMY, PHYSIOLOGY, AND HYGIENE. 

Experiments. 1st. To show the earthy without the animal 
matter, burn a bone in a clear fire for about fifteen minutes, 
and it becomes white and brittle, because the gelatin, or ani- 
mal matter of the bone, has been destroyed. 

2d. To show the animal without the earthy matter of the 
bones, immerse a slender bone for a few days in a weak acid, 
(one part muriatic acid and six parts water,) and it can then 
be bent in any direction. In this experiment, the acid has 
removed the earthy matter, (carbonate and phosphate of lime,) 
yet the form of the bone is unchanged. 

69. The bones are formed from the blood, and are sub- 
jected to several changes before they are perfected. At their 
early formative stage, they are cartilaginous. The vessels of 
the cartilage, at this period, convey only the lymph, or white 
portion of the blood ; subsequently, they convey red blood. 
At this time, true ossification (the deposition of phosphate and 
carbonate of lime) commences at certain points, which are 
called the points of ossification. 

70. Most of the bones are formed of several pieces, or 
centres of ossification. This is seen in the long bones which 
have their extremities separated from the body by a thin 
partition of cartilage. It is some time before these separate 
pieces are united to form one bone. 

71. When the process of ossification is completed, there 
is still a constant change in the bones. They increase in 
bulk, and become less vascular, until middle age. In ad- 
vanced life, the elevations upon their surface and near the 
extremities become more prominent, particularly in individ- 
uals accustomed to labor. As a person advances in years, 
the vitality diminishes, and in extreme old age, the earthy 

How can the earthy matter of the bones be shown ? The animal ? 
69. "What is the appearance of the bones in their early formative stage ? 
When does true ossification commence ? 70. How are most of the bones 
formed ? 71. What is said of the various changes of the bones after 
ossification ? 



ANATOMY OF THE BONES. 



31 



substance predominates ; consequently, the bones are ex- 
tremely brittle. 

72. The fibrous membrane that invests the bones is called 
per-i-os'te-um ; that which covers the cartilages is called 
per-i-chon'dri-um. When this membrane invests the skull, 
it is called per-i-cra'ni-um. 

Tig. 6. 




Fig. 6. A section of the knee-joint. The lower part of the femur, (thigh-bone,) 
and upper part of the tibia, (leg-bone,) are seen ossified at 1, 1. The cartilaginous 
extremities of the two bones are seen at d, d. The points of ossification of the 
extremities, are seen at 2, 2. The patella, or knee-pan, is seen at c. 3, A point, 
or centre of ossification. 



73. The periosteum is a firm membrane immediately in- 
vesting the bones, except where they are tipped with cartilage, 
and the crowns of the teeth, which are protected by enamel. 
This membrane has minute nerves, and when healthy, pos- 

72. What is the membrane called that invests the bones ? That covers 
the cartilage ? That invests the skull ? Explain fig. 6. 73. Describe the 
periosteum. 



32 ANATOMY, PHYSIOLOGY, AND HYGIENE. 

sesses but little sensibility. It is the nutrient membrane of 
the bone, endowing its exterior with vitality ; it also gives 
insertion to the tendons and connecting ligaments of the 
joints. 

74. There are two hundred and eight * bones in the human 
body, beside the teeth. These, for convenience, are divided 
into four parts : 1st. The bones of the Head. 2d. The bones 
of the Trunk. 3d. The bones of the Upper Extremities. 
4th. The bones of the Lower Extremities. 

75. The bones of the head are divided into those of the 
Skull, Ear, and Face. 

76. The skull is composed of eight bones. They are 
formed of two plates, or tablets of bony matter, united by a 
porous portion of bone. The external tablet is fibrous and 
tough ; the internal plate is dense and hard, and is called 
the vit're-ous, or glassy table. These tough, hard plates 
are adapted to resist the penetration of sharp instruments, 
while the different degrees of density possessed by the two 
tablets, and the intervening spongy bone, serve to diminish 
the vibrations that would occur in falls or blows. 

77. The skull is convex externally, and at the base much 
thicker than at the top or sides. The most important part of 
the brain is placed here, completely out of the way of injury, 
unless of a very serious nature. The base of the cranium, 
or skull, has many projections, depressions, and apertures ; 
the latter affording passages for the nerves and blood- 
vessels. 

* Some anatomists reckon more than this number, others less, for 
the reason that, at different periods of life, the number of pieces of 
which one bone is formed, varies. Example. The breast-bone, in 
infancy, has eight pieces; in youth, three; in old age, but one. 

74. How many bones in the human body ? How are they divided ? 
75 — 81. Give the anatomy of the bones of the head. 75. How are the bones 
of the head divided ? 76. Describe the bones of the skull. 77. What 
is the form of the skull ? What does the base of the skull present ? 



ANATOMY OF THE BONES. 33 

78. The bones of the cranium are united by ragged 
edges, called sutures. The edges of each bone interlock 
with each other, producing a union, styled, in carpentry, dove- 
tailing. They interrupt, in a measure, the vibrations pro- 
duced by external blows, and also prevent fractures from 
extending as far as they otherwise would, in one continued 
bone. From infancy to the twelfth year, the sutures are 
imperfect ; but, from that time to thirty-five or forty, they are 
distinctly marked ; in old age, they are nearly obliterated. 

Fig. 7. 




Fig. 7. 1, 1, The coronal suture at the front and upper part of the skull, or cra- 
nium. 2, The sagittal suture on the top of the skull. 3, 3, The lambdoidal suture 
at the back part of the cranium. 

79. We find as great a diversity in the form and texture 
of the skull-bone, as in the expression of the face. The head 
of the New Hollander is small ; that of the African is com- 
pressed ; while the Caucasian is distinguished for the beautiful 
oval form of the head. The Greek skulls, in texture, are 
close and fine, while the Swiss are softer and more open. 

78. How are the bones of the skull united ? What are the uses of the 
sutures ? Mention the appearance of the sutures at different ages. What 
does fig. 7 represent ? 79. What is said respecting the form and texture 
of the skull in different nations ? 



34 



ANATOMY, PHYSIOLOGY, AND HYGIENE. 



80. In each ear are four very small bones. They aid in 
hearing. 

81. In the face are fourteen bones, some of which serve 
for the attachment of powerful muscles, which are more or 
less called into action in masticating food ; others retain in 
place the soft parts of the face. 

Fig. 8 




Fig. 8. 1, The frontal, or bone of the forehead. 2. The parietal bone. 3, The 
temporal bone. 4, The zygomatic process of the temporal bone. 5, The malar 
(cheek) bone. 6, The superior maxillary bone, (upper jaw.) 7, The vomer, that 
separates the cavities of the nose. 8, The inferior maxillary bone, (lower jaw.) 
9, The cavity for the eye. 

82. The trunk has fifty-four bones — twenty-four Ribs ; 
twenty-four bones in the Spi'nal Column, (back-bone ;) four 
in the Pel'vis ; the Ster'num, (breast-bone ;) and the Os hy- 
oid'es, (the bone at the base of the tongue.) They are so 
arranged as to form, with the soft parts attached to them, two 
cavities, called the Tho'rax (chest) and Ab-do'men. 

80. How many bones in the ear ? 81. How many bones in the face ? 
"What is their use ? Explain fig. 8. 82 — 94. Give the anatomy of the bones 
of the trunk. 82. How many bones in the trunk ? Name them. What 
do they form by their arrangement ? 



ANATOMY OF TILE BONES. 35 

83. The thorax is formed by the sternum, in front ; the 
ribs, at the sides; and the twelve dorsal bones of the spinal 
column, posteriorly. The natural form of the chest is a cone, 
with its apex above ; but fashion, in many instances, has near- 
ly inverted this order. This cavity contains the lungs, heart, 
and large blood-vessels. 

Fig. 9. 



i8 7 




Fig. 9. 1, The first bone of the sternum, (breast-bone.) 2. The second bone of the 
sternum. 3, The cartilage of the sternum. 4, The first dorsal vertebra, (a bone of 
the spinal column.) 5, The last dorsal vertebra. 6, The first rib. 7, Its head. 
8, Its neck. 9, Its tubercle. 10, The seventh, or last true rib. 11, The cartilage 
of the third rib. 12, The floating ribs. 

84. The sternum is composed of eight pieces in the child. 
These unite and form but three parts in the adult. In youth, 
the two upper portions are converted into bone, while the 
lower portion remains cartilaginous and flexible until extreme 
old age, when it is often converted into bone. 

85. The ribs are connected with the spinal column, and in- 
crease in length as far as the seventh. From this they succes- 

83. Describe the thorax. Explain fig. 9. 84. Describe the sternum. 
85. Describe the ribs. 



OO ANATOMY, PHYSIOLOGY, AND HYGIENE. 

sively become shorter. The direction of the ribs from above, 
downward, is oblique, and their curve diminishes from the first 
to the twelfth. The external surface of each rib is convex ; the 
internal, concave. The inferior, or lower ribs, are, however, 
very flat. 

86. The seven upper ribs are united to the sternum, 
through the medium of cartilages, and are called the true ribs. 
The cartilages of the next three are united with each other, 
and are not attached to the sternum; these are called false 
ribs. The lowest two are called floating ribs, as they are not 
connected either with the sternum or the other ribs. 

87. The spinal column is composed of twenty-four pieces 
of bone. Each piece is called a vert'e-bra. On examining 
one of the bones, we find seven projections, called processes ; 
four of these, that are employed in binding the bones together, 
are called articulating processes ; two of the remaining are 
called the transverse ; and the other, the spinous. The last 
three give attachment to the muscles of the back. 

88. The large part of the vertebra, called the body, is 
round and spongy in its texture, like the extremity of the 
round bones. The processes are of a more dense character. 
The projections are so arranged that a tube, or canal, is formed 
immediately behind the bodies of the vertebrae, in which is 
placed the me-dul'la spi-na'lis, (spinal cord,) sometimes 
called the pith of the back-bone. 

89. Between these joints, or vertebrae, is a peculiar and 
highly elastic substance, which much facilitates the bending 
movements of the back. This compressible cushion of car- 
tilage also serves the important purpose of diffusing and 
diminishing the shock in walking, running, or leaping, and 
tends to protect the delicate texture of the brain. 

86. How are the ribs united to the sternum ? 87. Describe the spinal 
column. 88. Give the structure of the vertebra. "Where is the spinal 
cord placed ? 89. What is placed between each vertebra ? What is 
its use ? 



ANATOMY OF THE BONES. 37 

90. Another provision for the protection of the brain, 
which bears convincing proof of the wisdom and beneficence 
of the Creator, is the antero-posterior, or forward and back- 
ward curve of the spinal column. Were it a straight column, 
standing perpendicularly, the slightest jar, in walking, would 
cause it to recoil with a sudden jerk ; because, the weight 
bearing equally, the spine would neither yield to the one side 
nor the other. But, shaped as it is, we find it yielding in the 
direction of the curves, and thus the force of the shock is 
diffused. 

Fig. 10. Fig. 11. 





Fig. 10. A vertebra of the neck. 1, The body of the vertebra. 2, The spinal 
canal. 4, The spinous process, cleft at its extremity. 5, The transverse process. 
7, The inferior articulating process. 8, The superior articulating process. 

Fig. 11. 1, The cartilaginous substance that connects the bodies of the vertebrae. 
2. The body of the vertebra. 3, The spinous process. 4, 4, The transverse pro- 
cesses. 5, 5, The articulating processes. 6, 6, A portion of the bony bridge that 
assists in forming the spinal canal, (7.) 

Observation. A good idea of the structure of the vertebras 
may be obtained by examining the spinal column of a 
domestic animal, as the dog, cat, or pig. 

91. The pelvis is composed of four bones ; the two in- 
nom-i-na'ta, (nameless bones,) the sa'crum, and the coc'cyx. 

92. The lNNOMiNATUM, in the child, consists of three pieces. 

90. What is said of the curves of the spinal column ? "What is 
represented by fig. 10 ? By fig. 11 ? How can the structure of the vertebrse 
be seen ? 91. Of how many bones is the pelvis composed ? 92. What is 
said of the innominatum in the child ? 
4 



38 ANATOMY, PHYSIOLOGY, AND HYGIENE. 

These, in the adult, become united, and constitute but one 

bone. In the sides of these bones is a deep socket, or 

depression, like a cup, called the ac-e-tab'u-lum, in which the 

round head of the thigh-bone is placed. 

93. The sacrum, so called because the ancients offered it 

in sacrifices, is a wedge-shaped bone, that is placed between 

the irmominata, and to which it is bound by ligaments. Upon 

its upper surface it connects with the lower vertebra. At its 

inferior, or lower angle, it is united to the coccyx. It is 

concave upon its anterior, and convex upon its posterior 

surface. 

Ffc. 12. 




Fig. 12. 1, 1, The innominata, (nameless bones.) 2, The sacrum. 3, The coccyx. 
4, 4, The acetabulum, a, a, The pubic portion of the innominata. d, The arch of 
thepubes; c, The junction of the sacrum and lower lumbar vertebra. 

94. The coccyx, in infants, consists of several pieces, 
which, in youth, become united and form one bone. This is 
the terminal extremity of the spinal column. 

In the adult ? Describe the acetabulum. 93. Describe the sacrum. 
Explain fig. 12. 94. Describe the coccyx. 



ANATOMY OF THE BONES. 3\) 

CHAPTER V. 

ANATOMY OF THE BONES, CONTINUED. 

95. The bones of the upper and lower limbs are enlarged 
at each extremity, and have projections, or processes. To 
these, the tendons of muscles and ligaments are attached, 
which connect one bone with another. The shaft of these 
bones is cylindrical and hollow, and in structure, their exterior 
surface is hard and compact, while the interior portion is 
of a reticulated character. The enlarged extremities of the 
round bones are more porous than the main shaft. 

96. The upper extremities contain sixty-four bones — 
the Scap'u-la, (shoulder-blade ;) the Clav'i-cle, (collar-bone ;) 
the Hu'mer-us, (first bone of the arm ;) the Vl'na and Ra'di- 
W5, (bones of the fore-arm ;) the Car'pus, (wrist ;) the Met-a- 
car'pus, (palm of the hand ;) and the Pha-lan'ges, (fingers 
and thumb.) 

97. The clavicle is attached, at one extremity, to the 
sternum ; at the other, it is united to the scapula. It is shaped 
like the Italic f. Its use is to keep the arms from sliding 
toward the breast. 

98. The scapula is situated upon the upper and back part 
of the chest. It is flat, thin, and of a triangular form. This 
bone lies upon and is retained in its position by muscles. By 
their contractions it may be moved in different directions. 

99. The humerus is cylindrical, and is joined at the elbow 
with the ulna of the fore-arm ; at the scapular extremity, it is 

95 — 104. Give the anatomy of the bones of the upper extremities. 95. Give 
the structure of the bones of the extremities. 96. How many bones in 
the upper extremities ? Name them. 97- Give the attachments of the 
clavicle. What is its use ? 98. Describe the scapula. How is it re- 
tained in its position ? 99. Describe the humerus. 



40 



ANATOMY, PHYSIOLOGY, AND HYGIENE. 



lodged in the glenoid cavity, where, it is surrounded by a 
membranous bag, called the capsular ligament. 



Fig. 13. 



Fig. 14. 




Fig. 13. 1, The shaft of the humerus. 2, The large, round head that is placed in 
the glenoid cavity. 3, 4, Processes, to which muscles are attached. 5, A process, 
called the external elbow. 6, A process, called the internal elbow. 7, The articu- 
lating surface upon which the ulna rolls. 

Fig. 14. 1, The body of the ulna. 2, The shaft of the radius. 3, The upper 
articulation of the radius and ulna. 4, Articulating cavity, in which the lower 
extremity of the humerus is placed. 5, Upper extremity of the ulna, called the 
olecranon process, which forms the point of the elbow. 6, Space between the radius 
and ulna, filled by the intervening ligament. 7, Styloid process of the ulna. 8, Sur- 
face of the radius and the ulna, where they articulate with the bones of the wrist. 
9, Styloid process of the radius. 

100. The ulna articulates with the humerus at the elbow, 
and forms a perfect hinge-joint. This bone is situated on the 
inner side of the fore -arm. 



What is represented by fig. 13? By fig. 14? 100. Describe the ulna. 



ANATOMY OF THE BONES. 



41 



101. The radius articulates with the bones of the carpus, 
and forms the wrist-joint. This bone is situated on the out- 
side of the fore-arm, (the side on which the thumb is placed.) 
The ulna and radius, at their extremities, articulate with each 
other, by which union the hand is made to rotate, permitting 
its complicated and varied movements. 

102. The carpus is composed of eight bones, ranged in 
two rows, and so firmly bound together, as to permit only a 
small amount of movement. 



Fig. 15. 



Fig. 16. 





Fig. 15. u, The ulna. R, The radius, s, The scaphoid hone. L, The semilunar 
bone, c, The cuneiform bone, p, The pisiform bone. These four form the first row of 
carpal bones. T, T, The trapezium and trapezoid bones. M, The os magnum, u, The 
unciform bone. These four form the second row of carpal bones. 1, 1, 1, 1, 1, The 
metacarpal bones of the thumb and fingers. 

Fig. 16. 10, 10, 10, The metacarpal bones of the hand. 11, 11, First range of fin- 
ger-bones. 12, 12, Second range of finger-bones. 13, 13, Third range of finger-bones. 
14, 15, Bones of the thumb. 



103. The metacarpus is composed of five bones, upon four 
of which the first range of the finger-bones is placed ; and 



101. The radius. 102. How many bones in the carpus ? How are they 
ranged ? 103. Describe the metacarpus. 

4* 



42 ANATOMY, PHYSIOLOGY, AND HYGIENE. 

upon the other, the first bone of the thumb. The five meta- 
carpal bones articulate with the second range of carpal bones. 

104. The phalanges of the fingers have three ranges 
of bones, while the thumb has but two. 

Observation. The wonderful adaptation of the hand to all 
the mechanical offices of life, is one cause of man's superior- 
ity over the rest of creation. This arises from the size and 
strength of the thumbs, and the different lengths of the fingers. 

105. The lower extremities contain sixty bones — the 
Fe'mur, (thigh-bone ;) the Pa-tel'la, (knee-pan ;) the Tib'i-a, 
(shin-bone ;) the Fib'u-la, (small bone of the leg ;) the Tar'sus, 
(instep;) the Met-a-tar'sus, (middle of the foot;) and the Pha- 
lan'ges, (toes.) 

106. The femur is the longest bone in the system. It 
supports the weight of the head, trunk, and upper extremities. 
The large, round head of this bone is placed in the acetabu- 
lum. This articulation is a perfect specimen of the ball and 
socket joint. 

107. The patella is a small bone connected with the tibia 
by a strong ligament. The tendon of the ex-tens' or muscles 
of the leg is attached to its upper edge. This bone is placed 
on the anterior part of the lower extremity of the femur, and 
acts like a pulley, in the extension of the limb. 

108. The tibia is the largest bone of the leg. It is of a 
triangular shape, and enlarged at each extremity. 

109. The fibula is a smaller bone than the tibia, but of sim- 
ilar shape. It is firmly bound to the tibia, at each extremity. 

110. The tarsus is formed of seven irregular bones, which 
are so firmly bound together as to permit but little movement. 



104. How many ranges of bones have the phalanges ? 105 — 112. Give 
the anatomy of the bones of the lower extremities. 105. How many bones 
in the lower extremities ? Name them. 106. Describe the femur. 
107. Describe the patella. What is its function ? 108. What is the 
largest bone of the leg called ? What is its form ? 109. What is said 
of the fibula ? 110. Describe the tarsus. 



ANATOMY OF THE BONES. 

Fig. 17. Fig. 18. 



43 



Fig. 17. 1, The shaft of the femur, (thigh-bone.) 2, A projection, called the 
trochantar minor, to which are attached some strong muscles. 4, The trochantar 
major, to which the large muscles of the hip are attached. 3, The head of the fe- 
mur. 5, The external projection of the femur, called the external condyle. 6, The 
internal projection, called the internal condyle. 7, The surface of the lower extrem- 
ity of the femur, that articulates with the tibia, and upon which the patella slides. 

Fig. 18. 1, The tibia. .5, The fibula. 8, The space between the two, filled with 
the inter-osseous ligament. 6, The junction of the tibia and fibula at their upper 
extremity. 2, The external malleolar process, called the external ankle. 3, The 
internal malleolar process, called the internal ankle. 4, The surface of the lower 
extremity of the tibia, that unites with one of the tarsal bones to form the ankle-joint. 
7, The upper extremity of the tibia, upon which the lower extremity of the femur 
rests. 



Explain fig. 17. Explain fig. 18. 



44 



ANATOMY, PHYSIOLOGY, AND HYGIENE. 



111. The metatarsal bones are five in number. They 
articulate at one extremity with one range of tarsal bones ; at 
the other extremity, with the first range of the toe-bones. 

Fig. 19. 




14 13 



Fig. 19. A representation of the upper surface of the bones of the foot. 1, The 
surface of the astragulus, where it unites with the tibia. 2, The body of the astrag- 
ulus. 3, The calcis, (heel-bone.) 4, The scaphoid bone. 5, 6, 7, The cuneiform 
bones. 8, The cuboid. 9, 9, 9, The metatarsal bones. 10, The first bone of the great 
toe. 11, The second bone. 12, 13, 14, Three ranges of bones, forming the small 
toes. 



Fig. 20. 




Fig. 20. A side view of the bones of the foot, showing its arched form. The arch 
rests upon the heel behind, and the ball of the toes in front. 1, The lower part of the 
tibia. 2, 3, 4, 5, Bones of the tarsus. 6, The metatarsal bone. 7, 8, The bones of 
the great toe. These bones are so united as to secure a great degree of elasticity, or 
spring. 

Observation. The tarsal and metatarsal bones are united 
so as to give the foot an arched form, convex above, and con- 



Ill. Describe the metatarsal bones. Explain fig. 19. "What is repre- 
sented by fig. 20 ? "What is said of the arrangement of the bones of the 
foot? 



ANATOMY OF THE BONES. 



45 



cave below. This structure conduces to the elasticity of the 
step, and the weight of the body is transmitted to the ground 
by the spring of the arch, in a manner which prevents injury 
to the numerous organs. 

112. The phalanges (fig. 19) are composed of fourteen 
bones ; each of the small toes has three ranges of bones, 
while the great toe has but two. 

113. The joints form an interesting part of the body. In 
their construction, every thing shows the regard that has been 
paid to the security and the facility of motion of the parts thus 
connected together. They are composed of the extremities 
of two or more bones, Car'ti-lages, (gristles,) Syn-o'vi-al 
membrane, and Lig'a-ments. 



Fig. 22. 





Fig. 21. The relative position of the bones, cartilages, and synovial membrane. 
1, 1, The extremities of two bones that concur to form a joint. 2, 2, The carti- 
lages that cover the end of the bones. 3, 3, 3, 3, The synovial membrane which 
covers the cartilage of both bones, and is then doubled back from one to the other ; 
it is represented by the dotted lines. 

Fig. 22. A vertical section of the knee-joint. 1, The femur. 3, The patella. 
5, The tibia. 2, 4, The ligaments of the patella. 6, The cartilage of the tibia. 
12, The cartilage of the femur. * * * *, The synovial membrane. 



114. Cartilage is a smooth, solid, elastic substance, of a 
pearly whiteness, softer than bone. It forms upon the articu- 

112. Describe the phalanges. 113 — 118. Give the anatomy of the joints. 
113. "What is said of the joints ? Of what are the joints composed ? 
What is illustrated by fig. 21 ? By fig. 22 ? 114. Define cartilage. 



46 



ANATOMY, PHYSIOLOGY, AND HYGIENE. 



lar surfaces of the bones a thin incrustation, not more than 
the sixteenth of an inch in thickness. Upon convex surfaces 
it is the thickest in the centre, and thin toward the circum- 
ference ; while upon concave surfaces, an opposite arrange- 
ment is presented. 

115. The synovial membrane is a thin, membranous 
layer, which covers the cartilages, and is thence bent back, 
or reflected upon the inner surfaces of the ligaments which 
surround and enter into the composition of the joints. This 
membrane forms a closed sac. 



Fig. 23. 



Fior. 24. 





Fig. 23. The anterior ligaments of the knee-joint. 1, The tendon of the muscle 
that extends the leg. 2, The patella. 3, The anterior ligament of the patella, near 
its insertion. 4, 4, The synovial membrane. 5, The internal lateral ligament. 
6, The long external lateral ligament. 7, The anterior and superior ligament that 
unites the fibula to the tibia. 

Fig. 24. 2, 3, The ligaments that extend from the clavicle (1) to the scapula (4.) 
The ligaments 5, 6, extend from the scapula to the first bone of the arm. 

116. Beside the synovial membrane, there are numerous 
smaller sacs, called bur'sce mu-co'sa. These are often asso- 
ciated with the articulation. In structure, they are analogous 
to synovial membranes, and secrete a similar fluid. 

115. Describe the synovial membrane. 116. Describe the bursae mucosae. 
"What is represented by fig. 23 ? By fig. 24 ? 



ANATOMY OF THE BONES. 47 

117. The ligaments are composed of numerous straight 
fibres, collected together, and arranged into short bands of 
various breadths, or so interwoven as to form a broad layer, 
which completely surrounds the articular extremities of the 
bones, and constitutes a capsular ligament. These connect- 
ing bands are white, glistening, and inelastic. Most of the 
ligaments are found exterior to the synovial membrane. 

118. The bones, cartilages, ligaments, and synovial mem- 
brane are insensible when in health ; yet they are supplied 
with organic nerves, as well as with arteries, veins, and 
lymphatics. 

Observation. The joints of the domestic animals are similar 
in their construction to those of man. To illustrate this part 
of the body, a fresh joint of the calf or sheep may be used. 
After divesting the joints of the skin, the satin-like bands, or 
ligaments, will be seen passing from one bone to the other, 
under which may be observed the membranous bag, called the 
capsular ligament. This is very smooth, as it is lined with 
the soft synovial membrane, beneath which will be seen the 
cartilage, that may be cut with a knife, and under this the 
rough extremity of the ends of the bones. 

117. Of what are ligaments composed ? "What is the appearance of 
these bands? Where are they found? 118. With what vessels are the 
cartilages and ligaments supplied ? How can the structure of the joints 
be explained ? 



48 ANATOMY, PHYSIOLOGY, AND HYGIENE. 



CHAPTER VI. 

PHYSIOLOGY OF THE BONES. 

119. The bones are the framework of the system. By 
their solidity and form, they not only retain every part of the 
fabric in its proper shape, but afford a firm surface for the 
attachment of the muscles and ligaments. By means of the 
bones, the human frame presents to the eye a wonderful 
piece of mechanism, uniting the most finished symmetry of 
form with freedom of motion, and also giving security to 
many important organs. 

120. To give a clear idea of the relative uses of the bones 
and muscles, we will quote the comparison of another, though, 
as in other comparisons, there are points of difference. The 
" bones are to the body what the masts and spars are to the 
ship, — they give support and the power of resistance. The 
muscles are to the bones what the ropes, are to the masts and 
spars. The bones are the levers of the system ; by the 
action of the muscles their relative positions are changed. As 
the masts and spars of a vessel must be sufficiently firm to 
sustain the action of the ropes, so the bones must possess the 
same quality to sustain the action of the muscles in the 
human body." 

121. Some of the bones are designed exclusively for the 
protection of the organs which they enclose. Of this number 
are those that form the skull, the sockets of the eye, and the 
cavity of the nose. Others, in addition to the protection they 
give to important organs, are useful in movements of certain 

119 — 128. Give the physiology of the bones. 119. How may the bones be 
considered ? 120. To what may the bones be compared ? 121. Give the 
different offices of the bones. 



PHYSIOLOGY OF THE BONES. 49 

kinds. Of this class are the bones of the spinal column, and 
ribs. Others are subservient to motion. Of this class are the 
upper and lower extremities. 

122. The bones are subject to growth and decay ; to re- 
moval of old, useless matter, and the deposit of new particles, 
as in other tissues. This has been tested by the following 
experiment. Some of the inferior animals were fed with food 
that contained madder. In a few days, some of the animals 
were killed, and their bones exhibited an unusually reddish 
appearance. The remainder of the animals were, for a few 
weeks, fed on food that contained no coloring principle. 
When they were killed, their bones exhibited the usual color 
of such animals. The coloring matter, which had been de- 
posited, had been removed by the action of the lymphatics. 

123. The extremities of the bones that concur in forming 
a joint, correspond by having their respective configurations 
reciprocal. They are, in general, the one convex, and the 
other concave. In texture they are porous, and consequent- 
ly more elastic than if more compact. These are covered 
with a cushion of cartilage. The elastic character of these 
parts acts as so many springs, in diminishing the jar which 
important organs of the system would otherwise receive. 

124. The synovial membrane secretes a viscous fluid, 
which is called syn-o'vi-a. This lubricating fluid of the joints 
enables the surfaces of the bones and tendons to move smooth- 
ly upon each other, thus diminishing the friction consequent 
on their action. 

Observations. 1st. In this secretion is manifested the skill 
and omnipotence of the Great Architect ; for no machine of 
human invention supplies to itself, by its own operations, the 
necessary lubricating fluid. But, in the animal frame, it is 

122. "What is said of the change in bones ? How was it proved that 
there was a constant change in the osseous fabric ? 123. What is said of 
the extremities of the bones that form a joint ? 124. "What is synovia ? Its 
use ? "What is said of this lubricating fluid ? 

5 



50 



ANATOMY, PHYSIOLOGY, AND HYGIENE. 



supplied in proper quantities, and applied in the proper place, 
and at the proper time. 

2d. In some cases of injury and disease, the synovial fluid 
is secreted in large quantities, and distends the sac of the 
joint. This affection is called dropsy of the joint, and occurs 
most frequently in that of the knee. 

125. The function of the ligaments is to connect and bind 
together the bones of the system. By them the small bones 
of the wrist and foot, as well as the large bones, are as se- 
curely fastened as if retained by clasps of steel. Some of 
them are situated within the joints, like a central cord, or 
pivot, (3, fig. 26.) Some surround it like a hood, and con- 
tain the lubricating synovial fluid, (8, 9, fig. 25,) and some in 
the form of bands at the side, (5, 6, fig. 23.) 



Fig. 25. 



Fig. 26. 





Fig. 25. 8, 9, The ligaments that extend from the hip-bone (6) to the femur, (5.) 
Fig. 26. 2, The socket of the hip-joint. 5, The head of the femur, which is lodged 
in the socket. 3, The ligament within the socket. 

126. By the ligaments the lower jaw is bound to the tempo- 
ral bones, and the head to the neck. Thev extend the whole 



What is the effect when the synovial fluid is secreted in large quanti- 
ties ? 125. What is the function of the ligaments ? 126. Mention how the 
bones of the system are connected. 



PHYSIOLOGY OF THE BONES. 



51 



length of the spinal column, in powerful bands, on the outer 
surface, within the spinal canal, and from one spinous process 
to another. They bind the ribs to the vertebrse, to the trans- 
verse process behind, and to the sternum in front ; and this 
to the clavicle ; and this to the first rib and scapula ; and this 
last to the humerus. 

127. They also bind the two bones of the fore -arm at the 
elbow-joint ; and these to the wrist ; and these to each other 
and to those of the hand ; and these last to each other and 
to those of the fingers and thumb. In the same manner, they 
bind the bones of the pelvis together ; and these to the femur ; 
and this to the two bones of the leg and patella ; and so on, to 
the ankle, foot, and toes, as in the upper extremities. 




Fig. 27. 1, A front view of the lateral ligaments of the finger-joints. 2, A view 
of the anterior ligaments (a, b,) of the fingsr-joints. 3, A side view of the lateral 
ligaments of the finger-joints. 

128. The different joints vaiy in range of movement, and 
in complexity of structure. Some permit motions in all di- 
rections, as the shoulder ; some move in two directions, per- 
mitting only flexion and extension of the part, as the elbow ; 
while others have no movement, as the bones of the head in 
the adult. 



Explain fig. 27. 128. Describe the variety of movements in the different 
joints. 



52 



ANATOMY, PHYSIOLOGY, AND HYGIENE. 
Fig. 28. 




Fig. 28. 1, 1, The spinal column. 2, The skull. 3, The lower jaw. 4, The ster- 
num. 5, The ribs. 6, G, The cartilages of the ribs. 7, The clavicle. 8, The 
humerus. 9, The shoulder-joint. 10, The radius. 11, The ulna. 12, The elbow- 
joint. 13, The wrist. 14, The hand. 15, The haunch-bone. 16, The sacrum. 
17, The hip-joint. 18, The thigh-bone. 19, The patella. 20, The knee-joint. 
21, The fibula. 22, The tibia. 23, The ankle-joint. 24, The foot. 25, 26, The 
ligaments of the clavicle, sternum, and ribs. 27, 28, 29, The ligaments of the shoul- 
der, elbow, and wrist. 30, The large artery of the arm. 31, The ligaments of the 
hip-joint. 32, The large blood-vessels of the thigh. 33, The artery of the leg. 34, 
35, 33, The ligaments of the patella, knee, and ankle. 

Note. Let the pupil, in form of topics, review the anatomy and physiology of the 
bones from fig. 28, or from anatomical outline plates No. 1 and 2. 



HYGIENE OF THE BONES. 



CHAPTER VII. 

HYGIENE OE THE BONES. 

129. The hones increase in size and strength by use, while 
they are weakened by inaction. Exercise favors the deposi- 
tion of both animal and earthy matter, by increasing the 
circulation and nutrition in this texture. For this reason, the 
bones of the laborer are dense and strong, while those who 
neglect exercise, or are unaccustomed to manual employment, 
are deficient in size, and have not a due proportion of earthy 
matter to give them the solidity and strength of the laboring 
man. 

Observation. The tendons of the muscles are attached 
near the extremities of the bones. Exercise of the muscles 
increases the action of the vessels of that " part to which the 
tendons are attached, and thus increases the nutrition and size 
of this portion of the bone. Hence the joints of an indus- 
trious mechanic or farmer are larger than those of an indi- 
vidual who has not pursued manual vocations. 

130. The gelatinous bones of the child are not so well 
adapted for labor and severe exercise as those of an adult. 
1st. They are liable to become distorted. 2d. They are con- 
solidated by the deposition of earthy material before they are 
fully and properly developed. If a young animal, as the 
colt, be put to severe, continued labor, the deposition of earthy 

129 — 148. Give the hygiene of the bones. 129. What effect has exercise 
upon the bones ? What effect has inaction ? Why are the joints of the 
industrious farmer and mechanic larger than those of a person unac- 
customed to manual employment ? 130. Give the first reason why the 
bones of the child are not adapted to severe exercise. The second 
reason. 

5* 



54 ANATOMY, PHYSIOLOGY, AND HYGIENE. 

matter is hastened, and the bones are consolidated before 
they attain full growth. Such colts make small and inferior 
animals. Similar results follow, if a youth is compelled to 
toil unduly before maturity of growth is attained. On the 
other hand, moderate and regular labor favors a healthy 
development and consolidation of the bones. 

131. The kind and amount of labor should be adapted to the 
age, health, and development of the bones. Neither the flexi- 
ble bones of the child nor the brittle bones of the aged man 
are adapted, by their organization, to long-continued, and hard 
labor. Those of the one bend too easily, while those of the 
other fracture too readily. In middle age, the proportions of 
animal and earthy matter are, usually, such as to give the 
proper degree of flexibility, firmness, and strength for labor, 
with little liability to injury. 

132. The imperfectly developed bones of the young child 
will not bear long-continued exertions or positions without 
injury. Hence the requisitions of the rigid disciplinarian of 
schools, are unwise when he compels his pupils to remain in 
one position for a long time. He may have a " quiet school ; " 
but, not unfrequently, by such discipline, the constitution is 
impaired, and permanent injury is done to the pupils. 

133. The lower extremities, in early life, contain but a small 
proportion of earthy matter ; they bend when the weight of 
the body is thrown upon them for a long time. Hence, the 
assiduous attempts to induce children to stand or walk, either 
naturally or artificially, when very young, are ill advised, 
and often productive of serious and permanent evil. The 
" bandy" or bow legs are thus produced. 

"What effect has moderate, regular labor upon the growing youth ? 
131. What remark respecting the kind and amount of labor ? At what age 
are the bones best fitted for labor ? 132. What effect has long-continued 
exertions or positions on the bones of a child ? What is said of the requi- 
sitions of some teachers, who have the famed " quiet schools " ? 133. Why- 
should not the child be induced to stand or walk, either naturally or artifi- 
cially, at too early an age ? 



HYGIENE OF THE BONES. 



55 



134. The benches or chairs for children in a school-room 
should be of such a height as to permit the feet to rest on the floor. 
If the bench is so high as not to permit the feet to rest upon 
the floor, the weight of the limbs below the knee may cause 
the flexible bone of the thigh to become curved. ' The child 
thus seated, is inclined to lean forward, contracting an injuri- 
ous and ungraceful habit. Again, when the feet are not sup- 



Fisc 29. 



Fig. 30. 




Fig. 29. The position assumed when the seat is of proper height, and the feet 
supported. 

Fig. 30. The position a child naturally assumes when the seat is so high that the 
feet are not supported. 

ported, the child soon becomes exhausted, restless, and unfit 
for study. In the construction of a school-room, the benches 
should be of different heights, so as to be adapted to the dif- 
ferent pupils, and they should also have appropriate backs. 



134. What is said of the benches or chairs in a school-room ? What is 
represented by fig. 29 ? By fig. 30 ? What is the effect when the lower 
limbs are not supported ? 



56 



ANATOMY, PHYSIOLOGY, AND HYGIENE. 



135. Compression of the chest should he avoided. In chil- 
dren, and also in adults, the ribs are very flexible, and a small 
amount of pressure will increase their curvature, particularly at 
the lower part of the chest, and thus lessen the size of this 
cavity. The lower ribs are united to the breast-bone, by long, 
yielding cartilages, and compression may not only contract 
the chest, but an unseemly and painful ridge may be pro- 
duced, by the bending of the cartilages, on one or both sides 
of the sternum. 



Wis. 31. 



Hg. 32. 




Fig. 31. A natural and well-proportioned chest. 
Fig. 32. A chest fashionably deformed. 

136. Again, the cartilages on one side may be bent out- 
ward, while those on the opposite side are bent inward, thus 
forming a depression parallel with the sternum. In some in- 
stances, the anterior extremity of the lower ribs on each side 



135. Why should compression of the chest be avoided ? What is repre- 
sented by fig. 31 ? By fig. 32 ? 



HYGIENE OF THE BONES. 57 

are brought nearly or quite together. In these instances, the 
movable extremities of the ribs are drawn down toward the 
haunch-bones, while the space between the ribs is lessened. 
All this may be effected by tight or " snug " clothing. There- 
fore the apparel of a child should be loose, and supported 
over the shoulders, to avoid the before-mentioned evils. The 
same may be said of the clothing for adults. 

137. The erect position in sitting and standing should he 
assiduously ohserved. The spinal column, in its natural po- 
sition, curves from front to back, but not from side to side. 
The admirable arrangement of the bones, alternating with car- 
tilages, permits a great variety of motions and positions ; and 
when the spine is inclined to either side, the elasticity of its 
cartilages tends to restore it to its natural position. For this 
reason we may incline the spinal column in any direction for 
a short time, without danger of permanent curvature, if, af- 
terward, the erect position is assumed.* 

138. But if a stooping position, or a lateral curved posture, 
is continued for a long time, the spinal column does not easily 
recover its proper position, for the compressed edges of the 
cartilages lose their power of reaction, and finally one side of 
the cartilage becomes thinned, while the other is thickened ; 
and these wedge-shaped cartilages produce a permanent cur- 
vature of the spinal column. In a similar way, the student, 
seamstress, artisan, and mechanic acquire a stooping position, 
and become round shouldered, by inclining forward to bring 
their books or work nearer the eyes. 

139. Pupils, while writing, drawing, and sometimes while 



* Compare 1, 1, Fig. 28, with. 2, 2, 2, Fig. 48. 



136. May simply " snug " clothing compress the cartilages ? How should 
the apparel of a child be worn ? 137. In what direction does the spinal 
column, in its natural position, curve ? "What restores it to its natural 
position when curved laterally ? 138. What is the effect if a lateral curved 
position of the spinal column is continued for a long time ? 139. "When 
one shoulder is elevated for a long time, what is the effect upon the 
spinal column ? 



58 



ANATOMY, PHYSIOLOGY, AND HYGIENE. 



studying, frequently incline the spinal column to one side, in 
order to accommodate themselves to the desks at which they 
are seated. Often, these are higher than the elbow as it hangs 
from the shoulder while at rest. This attitude elevates one 
shoulder while it depresses the other ; consequently, the upper 

Fig. 33. 




Fig. 33. The table is^f proper height, the position is correct, and the spinal column, 
1, 1, is straight, while tile shoulders are of equal height. 

part of the spinal column is inclined toward the elevated 
shoulder, and the lower part is curved in the opposite direc- 
tion, giving the form of the letter S to the supporting column 
of the body. 



What does fig. 33 represent 



HYGIENE OF THE BONES. 



59 



Experiment. Let a pupil be placed at a desk or table with 
one elbow raised, as is frequently seen while writing, or at 
study, and observe the condition of the shoulder and spinal 
column in this position. Place another pupil at a table no 
higher than the elbow when it hangs by the side while sitting, 
and observe the appearance of the shoulders and spinal column. 
By a comparison of the two attitudes, the preceding remarks 
will be comprehended and appreciated. 

Fie. 34. 




Fig. 34. The table is too higfr, and the position is oblique and improper. The 
right shoulder is seen higher than the left, while the spinal column, 1, 1, exhibits 
three curves. 

140. One shoulder may be elevated, and no injurious results 



"What experiment is mentioned ? What does fig. 34 represent ? 140. How 
can one shoulder be elevated and no injurious results follow ? 



60 ANATOMY, PHYSIOLOGY, AND HYGIENE. 

follow, provided care is taken not to keep it in the raised posi- 
tion too long, or if the opposite shoulder is elevated for the 
same period of time. The right shoulder projects more fre- 
quently than the left. This arises from the greater use of the 
right hand with the shoulder elevated, and not unfrequently 
the oblique positions assumed in performing the daily voca- 
tions of life. With proper care, and by calling into action 
the left shoulder, this deformity can be prevented. 

Fig. 35. 




Fig. 35. A representation of a deformed trunk. 

141. The loss of symmetry and diminution of height from 
deformed spines are minor considerations, compared with the 
distortions that the chest experiences, thereby impairing res- 
piration and inducing diseases of the heart and lungs. The 

"Why does the right shoulder project more frequently than the left ? How 
can this deformity be prevented I 141. "What is said of deformed spinal 
columns ? 



HYGIENE OF THE BONES. 61 

invasion of the functions of these two important organs lessens 
the vitality of the whole system, and causes general ill health. 
Again, the curvature of the spinal column is frequently at- 
tended by irritation and disease of the spinal cord. 

142. Eminent physicians, both in this country and France, 
state that not more than one female in ten, who has been fash- 
ionably educated, is free from deformities of the shoulder or 
spinal column. Teachers, as well as mothers, should notice 
the positions of the child in performing the tasks allotted to 
it, whether studying or pursuing any employment. The fee- 
bler the organization of the child, the more frequently should 
there be a change of position. 

143. When a slight projection of the shoulder, with a cur- 
vature of the spine, exists, it can be improved by walking with 
a book, or something heavier, upon the head ; to balance which, 
the spinal column must be nearly erect. Those people that 
carry burdens upon their heads seldom have crooked spines. 

Observation. Persons from the North, in travelling through 
the Southern States, are surprised to see the heavy burdens 
that the porters carry on their heads. It is not unusual to see 
them walking at a rapid pace, with one or two trunks, weigh- 
ing fifty or eighty pounds each, upon their heads. Occasion- 
ally, we meet an itinerant toy-man, with his tray of fragile 
merchandise upon his head, walking with as much apparent 
security, as though his toys, or images, were in his hands. 
This is the easiest method of carrying burdens, because the 
position of the head and spinal column is erect. 

144. If the animal and earthy matter of the tones is not 
deposited in proper proportions, they are deficient in strength. 
If the gelatin predominates, the bones are weak, and be- 

142. "What statement by eminent physicians respecting deformities of the 
spine ? What caution to teachers and mothers ? 143. "Why should we 
stand and sit erect ? How may slight deformities of the spine be pre- 
vented ? "What is frequently noticed in travelling South ? 144. "What is 
the effect upon the bones when the gelatin preponderates ? 

6 



62 ANATOMY, PHYSIOLOGY, AND HYGIENE. 

come distorted. When nutrition is defective in the cylindri- 
cal bones, the heads are generally enlarged, and the shafts 
crooked ; if in the spinal column, it may be curved ; or in the 
cranium, it may be enlarged. This disease is familiarly known 
by the name of rickets. It is most common among those who 
have poor and insufficient food, live in dark, damp rooms, and 
breathe a vitiated air. The prevention and remedies for this 
disease are cleanliness, regular exercise, pure air, and nutri- 
tious food. 

145. When a bone is broken, some days elapse before the 
substance that reunites it is thrown out from the blood. In 
young persons, it may be "secreted during the second or third 
week, and in individuals advanced in life, usually during the 
third and fourth week. When the bone is uniting, during the 
second, third, or fourth week, the attention of a surgeon is 
more needed than during the first week. At this time, the 
ends of the bone should be placed together with accuracy, 
which requires the careful application of proper dressing. 
After the bones have united, it will take some weeks to 
consolidate the uniting material and render the " callus," or 
union, firm. During this time, the limb should be used with 
care. 

Observation. When a bone is fractured, a surgeon is imme- 
diately called, and the bone is " set." While the limb remains 
swelled and painful, the surgeon is required to attend and 
keep the dressings (bandages and spliftts) on. When the 
swelling has abated, and the pain subsided, frequently the 
patient intimates to the surgeon that his services can be 
dispensed with, as the " limb is doing well." This is the most 
important period, as the bone is uniting, and, unless the ends 
are nicely adjusted, the dressing properly applied, the person 

What is one cause of rickets ? What are the prevention and remedies 
for this disease ? 145. Does the time vary when the reuniting substance 
of the bone is secreted from the blood ? When is the surgeon's care most 
needed ? Why ? 



HYGIENE OF THE BONES. 63 

will find, on recovery, a shortened and crooked limb. The 
surgeon is then censured, when he is not blamable. 

146. It is seldom that a bone is displaced without injury 
to the connecting ligaments and membranes. When these 
connecting bands are lacerated, pain, swelling, and other 
symptoms indicating inflammation succeed, which should be 
removed by proper treatment, directed by a surgical adviser. 

147. In sprains, but few, if any, of the fibres of the con- 
necting ligaments are lacerated ; but they are unduly strained 
and twisted, which occasions acute pain at the time of the 
injury. This is followed by inflammation and weakness of the 
joints. The treatment of these injuries is similar to that of a 
dislocated bone after its reduction. The most important item 
in the treatment during the few first days, is rest. 

148. In persons of scrofulous constitutions, and those in 
whom the system is enfeebled by disease, white swellings and 
other chronic diseases of the joints frequently succeed sprains. 
Such persons cannot be too assiduous in adopting a proper and 
early treatment of injured joints. 

146. What parts are injured in the displacement of a bone ? 147. What 
causes the acute pain in sprains ? What is a good remedy for this kind 
of injury ? 148. What caution to persons of scrofulous constitutions ? 



64 ANATOMY, PHYSIOLOGY, AND HYGIENE. 

CHAPTER VIII. 

THE MUSCLES. 

149. All the great motions of the body are caused by the 
movement of some of the bones which form the framework 
of the system ; but. these, independently of themselves, have 
not the power of motion, and only change their position 
through the action of other organs attached to them, which, by 
contracting, draw the bones after them. In some of the slight 
movements, as the winking of the eye, no bones are displaced. 
These moving, contracting organs are the Mus'cles, (lean 
meat.) 

ANATOMY OF THE MUSCLES. 

150. The muscles, by their size and number, constitute the 
great bulk of the body, upon which they bestow form and 
symmetry. In the limbs, they are situated around the bones, 
which they invest and defend, while they form, to some of the 
joints, their principal protection. In the trunk, they are spread 
out to enclose cavities, and constitute a defensive wall, capa- 
ble of yielding to internal pressure, and reassuming its origi- 
nal state. 

151. In structure, a muscle is composed of fas-cic'u-U 
(bundles of fibres) of variable size. These are enclosed in a 
cellular membranous investment, or sheath. Every bundle is 
composed of a number of small fibres, and each fibre con- 
sists of a number of filaments, each of which is enclosed in 

149. How are all the motions of the body produced ?- What are these 
motor organs called ? 150 — 160. Give the anatomy of the muscles. 
150. What is said of the muscles ? 151. Give their structure. 



ANATOMY OF THE MUSCLES. 



65 



a delicate sheath. Toward the extremity of the organ the 
muscular fibre ceases, and the cellular structure becomes 
aggregated, and so modified as to constitute ten'dons, (cords,) 
by which the muscle is tied to the surface of the bone. The 
union is so firm, that, under extreme violence, the bone will 
sooner break than permit the tendon to separate from its 
attachment. In some situations, there is an expansion of the 
tendon, in the manner of a membrane, called Ap-o-neu-ro'sis, 
or Fas'ci-a. 

Observation. The pupil can examine a piece of boiled 
beef, or the leg of a fowl, and see the structure of the 
fibres and tendons of a muscle. 




Fig. 36. 1, A representation of the direction and arrangement of the fibres in a 
fusiform, or spindle-shaped muscle. 2, In a radiated muscle. 3, In a penniform 
muscle. 4, In a bipenniform muscle, t, t, The tendons of a muscle. 

152. Muscles present various modifications in the arrange- 
ment of their fibres, as relates to their tendinous structure. 
Sometimes they are completely longitudinal, and terminate, at 
each extremity, in a tendon, the entire muscle being spindle- 
shaped. In other situations, they are disposed like the rays of 



How are tendons or cords formed ? What is the expansion of a tendon 

called r How can the structure of muscles and their fibres be shown ? 

"What does fig. 36 represent ? 152. Give the different arrangements of 
muscular fibres. 

6* 



66 



ANATOMY, PHYSIOLOGY, AND HYGIENE. 



a fan, converging to a tendinous point, and constituting a 
ra'di-ate muscle. Again they are pen'ni-for?n, converging, 
like the plumes of a pen, to one side of a tendon, which runs 
the whole length of the muscle ; or they are bi-pen'ni-form, 
converging to both sides of the tendon. 

153. In the description of a muscle, its attachments are 
expressed by the terms "origin" and "insertion." The 
term origin is generally applied to the more fixed or central 
attachment, or to the point toward which motion is directed ; 
while insertion is assigned to the more movable point, or to 
that most distant from the centre. The middle, fleshy portion 
is called the " belly," or " swell." The color of a muscle 
is red, which is characteristic of flesh ; and each fibre is 
supplied with arteries, veins, lymphatics, and both sensitive 
and motor nervous filaments. 

154. The fascia is of various extent and thickness, dis- 
tributed through the different regions of the body, for the pur- 
pose of investing and protecting the softer and more delicate 
organs. An instance is seen in the membrane which en- 
velopes a leg of beef, and which is observed on the edges of 
the slices when it is cut for broiling. When freshly exposed, 
it is brilliant in appearance, tough, and inelastic. In the limbs 
it forms distinct sheaths to all the muscles. 

155. This tendinous membrane assists the muscles in their 
action, by keeping up a tonic pressure on their surface. It 
aids materially in the circulation of the fluids, in opposition 
to the laws of gravity. In the palm of the hand and sole of 
the foot, it is a powerful protection to the structures that enter 
into the formation of these parts. In all parts of the system, 
the separate muscles are not only invested by fascia, but they 

153. "What is meant by the origin of a muscle ? The insertion ? The 
swell ? What is the color of muscles ? With what is each muscular fibre 
supplied ? 154. What is said of fascia ? What is its appearance when 
freshly exposed ? 155. What effect has it on the muscles ? Give other 
uses of the fascia. 



ANATOMY OF THE MUSCLES. 



67 



are arranged in layers, one over another. The sheath of each 
muscle is loosely connected with another, by the cellular 
membrane. 

156. The interstices between the different muscles are 
filled with adipose matter, or fat. This is sometimes called 
the packing of the system. To the presence of this tissue, 
youth are indebted for the roundness and beauty of their 

limbs. 

Fig. 37. 




Fig. 37. A transverse section of the neck. The separate muscles, as they are 
arranged in layers, with their investing fascia?, are beautifully represented. As 
the system is symmetrical, figures are placed only on one side. In the trunk the 
muscles are arranged in layers, surrounded by fasciae, as in the neck. The same 
is true of the muscles of the upper and lower limbs. 

12, The trachea, (windpipe.) 13, The oesophagus, (gullet.) 14, The carotid artery and 
jugular vein. 28, One of the bones of the spinal column. The figures that are placed 
in the white spaces represent some of the fascias ; the other figures indicate muscles. 

157. The muscles may be arranged, in conformity with the 
general division of the body, into four parts : 1st. Those of 
the Head and Neck. 2d. Those of the Trunk. 3d. Those 
of the Upper Extremities. 4th. Those of the Lower Ex- 
tremities. 



156. Give a reason why the limbs of youth are rounder than those of the 
aged. Describe fig. 37. 



68 ANATOMY, PHYSIOLOGY, AND HYGIENE. 

Fig. 38. 




Fig. 38. The superficial layer of muscles on the face and neck. 1, 1, The occipito- 
frontalis muscle. 2, The orbicularis palpebrarum. 6, The levator labii superioris. 
7, The levator anguli oris. 8, The zygomaticus minor. 9, The zygomaticus major. 
10, The masseter. 11, The depressor labii superioris. 13, The orbicularis oris. 
15, The depressor anguli oris. 16, The depressor labii inferioris. 18, The sterno- 
hyoideus. 19, The platysma-myodes. 20, The superior belly of the omo-hyoideus. 
21, The sterno-cleido mastoideus. 22, The scalenus medius. 23, The inferior belly 
of the omo-hyoideus. 24, The trapezius.* 

Practical Explanation. The muscle 1, 1, elevates the eyebrows. The muscle 2 
closes the eye. The muscle 6 elevates the upper lip. The muscles 7, 8, 9, elevate 
the angle of the mouth. The muscle 10 brings the teeth together when eating. The 
muscle 11 depresses the upper lip. The muscle 13 closes the mouth. The muscle 
15 depresses the angle of the mouth. The muscle 16 draws down the lower lip. 
The muscles 18, 19, 20, 23, depress the lower jaw, or elevate the larynx and sternum. 
The muscle 21, when both sides contract, draws the head forward, or elevates the 
sternum ; when only one contracts, the face is turned one side toward the opposite 
shoulder. The muscles 18, 19, 20, 21, 22, 23, 24, aid in respiration. 

* In the plates illustrating the muscular system, the names of such muscles are 
given as are referred to in the paragraph " Practical Explanation." These names need 
not be committed to memory. If a pupil wishes to acquire a knowledge of the 
general attachment of the muscles represented in the plates, he can do so by com- 
paring the muscular plate with that of the skeleton, (fig. 28.) 



ANATOMY OF THE BIUSCLES. 69 

Observation. When we are sick, and cannot take food, 
the body is sustained by absorption of the fat. The removal 
of it into the blood causes the sunken cheek, hollow eye, and 
prominent appearance of the bones after a severe illness. 

158. The number of muscles in the human body is more 
than five hundred ; in general, they form about the skeleton 
two layers, and are distinguished into superficial and deep- 
seated muscles. Some of the muscles are voluntary in their 
motions, or act under the government of the will, as those 
which move the fingers, limbs, and trunk ; while others are 
involuntary, or act under the impression of their proper stimu- 
lants, without the control of the individual, as the heart. 

Observations. 1st. The abdominal muscles are expiratory, 
and the chief agents for expelling the residuum from the rec- 
tum, the bile from the gall bladder, the contents of the stomach 
and bowels when vomiting, and the mucus and irritating sub- 
stances from the bronchial tubes, trachea, and nasal passages 
by coughing and sneezing. To produce these effects they all 
act together. Their violent and continued action sometimes 
produces hernia, and, when spasmodic, may occasion ruptures 
of the different organs. 

2d. The contraction and relaxation of the abdominal mus- 
cles and diaphragm stimulate the stomach, liver, and intestines 
to a healthy action, and are subservient to the digestive powers. 
If the contractility of their muscular fibres is destroyed or 
impaired, the tone of the digestive apparatus will be diminished, 
as in indigestion and costiveness. This is frequently attended 
by a displacement of those organs, as they generally gravitate 
to the lower portion of the abdominal cavity, when the sus- 
taining muscles lose their tone and become relaxed. 



What causes the hollow eye and sunken cheek after a severe sickness ? 
158. How many muscles in the human system ? Into how many layers are 
they arranged ? "What is a voluntary muscle ? Give examples. "What is 
an involuntary muscle ? Mention examples. Give observation 1st, respect- 
ing the use of the abdominal muscles ? Observation 2d, 



70 



ANATOMY, PHYSIOLOGY, AND HYGIENE. 
Fig. 39. 




Fig. 391 A front view of the muscles of the trunk. On the left side the superficial 
layer is seen; on the right, the deep layer. 1, The pectoralis major muscle. 2, The 
deltoid muscle. 6, The pectoralis minor muscle. 9, The coracoid process of the 
scapula. 11, The external intercostal muscle. 12, The external oblique muscle. 
13, Its aponeurosis. 16, The rectus muscle of the right side. 18, The internal 
oblique muscle. 

Practical Explanation. The muscle 1 draws the arm by the side, and across the 
chest, and likewise draws the scapula forward. The muscle 2 elevates the arm. The 
muscle 6 elevates the ribs when the scapula is fixed, or draws the scapula forward 
and downward when the ribs are fixed. The muscles 12, 16, 18, bend the body for- 
ward or elevate the hips when the muscles of both sides act. They likewise depress 
the ribs in expiration.' When the muscles on only one side act, the body is twisted to 
the same side. 



Explain fig. 39. Give the function of some of the most prominent 
muscles, from this figure. 



ANATOMY OF THE MUSCLES. 
Kir, 40. 



71 




Fig. 40. A lateral view of the muscles of the trunk. 3, The upper part of the 
external oblique muscle. 4, Two of the external intercostal muscles. 5, Two of the 
internal intercostals. 6, The transversalis muscle. 7, Its posterior aponeurosis. 
8, Its anterior aponeurosis. II, The right rectus muscle. 13, The crest of the 
ilium, or haunch-bone. 

Practical Explanation. The rectus muscle, 11, bends the thorax upon the abdomen 
when the lower extremity of the muscle is the fixed point ; but when the upper ex- 
tremity is the fixed point, the effect is to bring forward and raise the pelvis and lower 
extremities. They likewise depress the ribs in respiration. The transverse muscle, 
6,7, 8, lessens the cavity of the abdomen, and presses the intestines, stomach, and 
liver upward, against the diaphragm, in expiration. 

3d. The region of the back, in consequence of its extent, is 
common to the neck, the upper extremities, and the abdomen. 
The muscles of which it is composed are numerous, and are 
arranged in six layers. 



What is represented by fig. 40 ? 
muscles represented by this figure. 



Give the function of some of the 



72 ANATOMY. PHYSIOLOGY, AND HYGIENE. 

Fig. 41. 




Fig. 41. The first, second, and part of the third layer of muscles of the back. 
The first layer is shown on the right, and the second on the left side. 1, The tra- 
pezius muscle. 2, The spinous processes of the vertebras. 3, The acromion process 
and spine of the scapula. 4, The latissimus dorsi muscle. 5, The deltoid muscle. 
7, The external oblique muscle. 8, The gluteus medius muscle. 9, The gluteus 
maximus muscle. 11, 12, The rhomboideus major and minor muscles. 15, The 
vertebral aponeurosis. 16, The serratus posticus inferior muscle. 22, The serratus 
magnus muscle. 23, The internal oblique muscle. 

Practical Explanation. The muscles 1, 11, 12, draw the scapula back toward the spine. 
The muscles 11, 12, draw the scapula upward toward the head, and slightly back- 
ward. The muscle 4 draws the arm by the side, and backward. The muscle 5 
elevates the arm. The muscles 8, 9, extend the thigh on the body. The muscle 1 
draws the head back and elevates the chin. The muscle 16 depresses the ribs iD 
expiration. The muscle 22 elevates the ribs in inspiration. 



ANATOMY OF THE MUSCLES. 73 

159. The diaphragm, or midriff, is trie muscular division 
between the thorax and the abdomen. It is penetrated by the 
oesophagus on its way to the stomach, by the aorta conveying 
blood toward the lower extremity, and by the ascending vena 
cava, or vein, on its way to the heart. 

Fi S . 42. 




Fig. 42. A representation of the under, or abdominal side of the diaphragm. 
1, 2, 3, 4, The portion which is attached to the margin of the ribs. 8, 10, The two 
fleshy pillars of the diaphragm, which are attached to the third and fourth lumbar 
vertebra?. 9, The spinal column. 11, The opening for the passage of the aorta. 
12, The opening for the oesophagus. 13, The opening for the ascending vena cava, 
or vein. 

Observation. The diaphragm may be compared to an in- 
verted basin, its bottom being turned upward into the thorax, 
while its edge corresponds with the outline of the edges of the 
lower ribs and sternum. Its concavity is directed toward the 
abdomen, and thus, this cavity is very much enlarged at the 
expense of that of the chest, which is diminished to an equal 
extent. 

159. Describe the diaphragm. What vessels penetrate this muscular 
septum ? 

7 



74 



ANATOMY, PHYSIOLOGY, AND HYGIENE. 



160. " The motions of the fingers do not merely result from 
the action of the large muscles which lie on the fore-arm, 
these being concerned more especially in the stronger actions 
of the hands. The finer and more delicate movements of 
the fingers are performed by small muscles situated in the 
palm and between the bones of the hand, and by which the 
fingers are expanded and moved in all directions with wonder- 
ful rapidity." 

Pig. 43. Fig. 44. 





Fig. 43. A front view of the superficial layer of muscles of the fore-arm. 5, The 
flexor carpi radialis muscle. 6, The palmaris longus muscle. 7, One of the fasci- 

160. Where are the muscles situated that effect the larger movements of the 
hand ? That perform the delicate movements of the fingers ? Give the use 
of some of the muscles represented by fig. 43. Those represented by fig. 44. 



ANATOMY OF THE MUSCLES. 75 

culi of the flexor sublimis digitorum muscle, (the rest of the muscle is seen beneath 
the tendons of the pa! maris longus.) 8, The flexor carpi ulnaris muscle. 9, The 
palmar fascia. 11, The abductor pollicis muscle. 12, One portion of the flexor 
brevis pollicis muscle. 13, The supinator longus muscle. 14, The extensor ossis 
metacarpi, and extensor primi internodii pollicis muscles, curving around the lower 
border of the fore-arm. 15, The anterior portion of the annular ligament, which 
binds the tendons in their places. 

Practical Explanation. The muscles 5, 6, 8, bend the wrist on the bones of the fore- 
arm. The muscle 7 bends the second range of finger-bones on the first. The mus- 
cle 11 draws the thumb from the fingers. The muscle 12 flexes the thumb. The 
muscle 13 turns the palm of the hand upward. The muscles 8, 13, 14, move the 
hand laterally. 

Fig. 44. A back view of the superficial layer of muscles of the fore-arm. 5, The 
extensor carpi radialis longior muscle. 6, The extensor carpi radialis brevior 
muscle. 7, The tendons of insertion of these two muscles. 8, The extensor com- 
munis digitorum muscle. 9, Tiie extensor minimi digiti muscle. 10, The extensor 
carpi ulnaris muscle. 13, The extensor ossis metacarpi and extensor primi inter- 
nodii muscles, lying together. 14, The extensor secundi internodii muscle; its 
tendon is seen crossing the two tendons of the extensor carpi radialis longior and 
brevior muscles. 15, The posterior annular ligament. The tendons of the common 
extensor muscle of the fingers are seen on the back of the hind, and their mode of 
distribution on the back of the fingers. 

Practical Explanation. The muscles 5, 6, 10, extend the wrist on the fore-arm. The 
muscle 8 extends the fingers. The muscle 9 extends the little finger. The muscles 

13 extend the metacarpal bone of the thumb, and its first phalanx. The muscle 

14 extends the last bone of the thumb. The muscles 10, 13, 14, move the hand 
laterally. 



76 ANATOMY, PHYSIOLOGY, AND HYGIENE. 

CHAPTER IX. 

PHYSIOLOGY OF THE MUSCLES. 

161. The muscles exercise great influence upon the sys- 
tem. It is by their contraction that we are enabled to pursue 
different employments. By their action the farmer cultivates 
his fields, the mechanic wields his tools, the sportsman pursues 
his game, the orator gives utterance to his thoughts, the lady 
sweeps the keys of the piano, and the young are whirled in 
the mazy dance. As the muscles bear so intimate a relation 
to the pleasures and employments of man, a knowledge of 
the laws by which their action is governed, and the conditions 
upon which their health depends, should be possessed by all. 

162. The peculiar characteristic of muscular fibres is 
contractility, or the power of shortening their substance on 
the application of stimuli, and again relaxing when the stim- 
ulus is withdrawn. This is illustrated in the most common 
movements of life. Call into action the muscles that elevate 
the arm, by the influence of the ivill, or mind, (the common 
stimulus of the muscles,) and the hand and arm are raised ; 
withdraw this influence by a simple effort of the will, and the 
muscles, before rigid and tense, become relaxed and yielding. 

163. The contractile effect of the muscles, in producing the 
varied movements of the system, may be seen in the bending 
of the elbow. The tendon of one extremity of the muscle is 
attached to the shoulder-bone, which acts as a fixed point ; the 
tendon of the other extremity is attached to one of the bones 

161 — 172. Give the physiology of the muscles. 161. What are some of the 
influences exerted by the muscles on the system ? 162. What is peculiar 
to muscular fibres ? How is this illustrated ? 163. Explain how the move- 
ments of the system are effected by the contraction of the muscles. 



PHYSIOLOGY OF THE MUSCLES. 77 

of the fore-arm. When the swell of the muscle contracts, or 
shortens, its two extremities approach nearer each other, and 
by the approximation of the terminal extremities of the mus- 
cle, the joint at the elbow bends. On this principle, all the 
joints of the system are moved. This is illustrated by fig. 45. 

Fig. 45. 




2 

Fig. 45. A representation of the manner in which all of the joints of the body are 
moved. 1, The bone of the arm above the elbow. 2, One of the bones below the 
elbow. 3, The muscle that bends the elbow. This muscle is united, by a tendon, to 
the bone below the elbow, (4:) at the other extremity, to the bone above the elbow, 
(5.) 6, The muscle that extends the elbow. 7, Its attachment to the point of the 
elbow. 8, A weight in the hand to be raised. The central part of the muscle 
3 contracts, and its two ends are brought nearer together. The bones below the 
elbow are brought to the lines shown by 9, 10, 11. The weight is raised in the 
direction of the curved line. When the muscle 6 contracts, the muscle 3 relaxes, 
and the fore-arm is extended. 

Experiments. 1st. Clasp the arm midway between the 
shoulder and elbow, with the thumb and fingers of the 
opposite hand. When the arm is bent, the inside muscle 
will become hard and prominent, and its tendon at the elbow 
rigid, while the muscle on the opposite side will become 
flaccid. Extend the arm at the elbow, and the outside muscle 
will swell and become firm, while the inside muscle and its 
tendon at the elbow will be relaxed. 

Explain fig. 45. Give experiment 1st. 

7* 



78 ANATOMY, PHYSIOLOGY, AND HYGIENE. 

2d. Clasp the fore-arm about three inches below the 
elbow, then open and shut the fingers rapidly, and the swell- 
ing and relaxation of the muscles on the opposite sides of the 
arms, alternating with each other, will be felt, corresponding 
with the movement of the ringers. While the fingers are 
bending, the inside muscles swell, and the outside ones be- 
come flaccid ; and, while the fingers are extending, the inside 
muscles relax, and the outside ones swell. The alternate 
swelling and relaxation of antagonist muscles may be felt in 
the different movements of the limbs. 

164. Each fibre of the several muscles receives from the 
brain, through the nervous filament appropriated to it, a cer- 
tain influence, called nervous fluid, or stimulus. It is this that 
induces contraction, while the suspension of this stimulus 
causes relaxation of the fibres. By this arrangement, the 
action of the muscular system, both as regards duration and 
power, is, to a limited extent, under the control of the mind. 
The more perfect the control, the better the education of the 
muscular system ; as is seen in the graceful, effective, and 
well-educated movements of musicians, dancers, skaters, &c. 

165. The length of time which a muscle may remain con- 
tracted, varies. The duration of the contraction of the volun- 
tary muscles, in some measure, is in an inverse ratio to its 
force. If a muscle has contracted with violence, as when 
great effort is made to raise a heavy weight, relaxation will 
follow sooner than when the contraction has been less power- 
ful, as in raising light bodies. 

166. The velocity of the muscular contraction depends on 
the will. Many of the voluntary muscles in man contract 
with great rapidity, so that he is enabled to utter distinctly 



Give experiment 2d. 164. With what is each muscular fibre supplied ? 
What effect has this stimulus on the muscles ? 165. How long does a vol- 
untary muscle remain contracted ? 166. On what is the velocity of mus- 
cular contraction dependent ? How many letters may be pronounced in a 
minute ? 



PHYSIOLOGY OF THE MUSCLES. 79 

fifteen hundred letters in a minute ; the pronunciation of each 
letter requiring both relaxation and contraction of the same 
muscle, thus making three thousand actions in one minute. 
But the contraction of the muscles of some of the inferior 
animals surpasses in rapidity those of man. The race-horse, 
it is said, has run a mile in a minute ; and many birds of prey 
will probably pass not less than a thousand miles daily. 

167. The functions of the involuntary muscles are neces- 
sary to the digestion of food, the absorption and circulation of 
the nutritive fluids. They could not be trusted with safety to 
the control of the will, lest the passions or the indiscretions of 
the person should continually avert those operations so neces- 
sary to health, and even to life. The Divine Builder of this 
complicated machine has wisely ordered that the muscles 
upon which these motions depend, shall act under the impres- 
sion of their proper stimulants, without the control of the 
individual. 

168. Again, there are certain operations which could not 
be safely intrusted to the absolute government of the voluntary 
muscles, or entirely removed from their control. Thus life 
can be supported only a few minutes without breathing ; but 
it would be impossible to perform the daily vocations of life 
if we were compelled to breathe at all times, or at perfectly 
regular intervals. 

169. It has been observed that, among men of the same 
size, a wide difference exists in their strength and activity 
— qualities which depend upon the size and number of the 
nerves, the size and activity of the brain, and the education, 
or training of the muscles. Men having large nerves leading 

How many contractions and relaxations of the same muscle ? What is 
said of the rapidity of muscular contractions in other animals ? 167. "When 
are the involuntary muscles called into action ? "Why -would it not have 
been safe to trust these important operations to the exclusive control of the 
•will ? 168. Give an instance where some of the muscles act under the 
government of the will, conjoined with those that are involuntary. 169. On 
what does the difference in muscular activity and strength depend ? 



80 



ANATOMY, PHYSIOLOGY, AND HYGIENE. 



to the muscles, with the brain active, and muscles well trained, 
will perform feats of strength and agility, that other men, of 
the same size, cannot effect. Rope-dancers, harlequins, and 
other performers of feats, are persons thus constituted. 

170. Persons with small muscles, and largely developed 
nervous systems, will sometimes exhibit very great muscular 
power for a time; but it will not be of long continuance, 
unless the brain is functionally diseased, as in hysteria, 
delirium of fever, insanity, &c. Men of large muscles and 
small nerves can never perform feats of great strength ; but 
they have the power of endurance, and are better capacitated 
for continued labor. Thus we cannot judge of the ability of 
persons to make exertions and continue them, by their stature 
alone. Strength, and the power of endurance, are the result 
of a combination of well-developed muscles, large nerves, 
and a full-sized, healthy, and active brain. 

Observation. The muscles of fishes are large, and the 
nerves distributed to them, comparatively small. The mus- 
cles of birds are small, but their fibres are very compact. 
The nerves appropriated to the muscles that are called into 
action in flying, are large as well as numerous. 

171. The contractile portion, or swell of the muscle, is in 
general at a distance from the part to be moved. Thus the 
principal muscles that move the fingers are situated upon the 
arm. This disposition of the muscles, together with the 
attachment of the tendons of the muscles near the joint to be 
moved, (fig. 45,) permits only a small angle for the action of 
the muscular fibres. By these arrangements there is a loss 
of power ; but we are compensated for this disadvantage by 
increased celerity of movement, beauty of form, and adapta- 
tion of the limbs to the varied pursuits of man. 

170. "What is said of those persons who have small muscles and largely 
developed nervous systems ? Of those who have large muscles and small 
nerves ? Upon what do strength and the power of endurance depend ? 
171. Why is there a loss of power in the action of the muscles ? 



PHYSIOLOGY OF THE MUSCLES. 81 

Illustration. The muscle that bends the elbow acts at a 
disadvantage of twenty to one. If we bend the elbow with a 
weight of fifty pounds in the hand, the muscle contracts with a 
power that would be adequate to raise one thousand pounds 
if acted upon at right angles. 

172. The number of muscles which are called into action 
in the movements of the different joints, varies. The hinge- 
joints, as the elbow, have two sets of muscles — one to bend 
the joint, the other to extend it. The ball and socket joints, 
as the shoulder, are not limited to mere flexion and extension. 
No joint in the system has the range of movement that is 
possessed by that of the shoulder. By the action of the 
muscles attached to the arm, it is not only carried upward and 
forward, but forward and backward. Hence the arm may be 
moved at any angle, by a combined action of its muscles. 

Observation. " Could we behold properly the muscular 
fibres in operation, nothing, as a mere mechanical exhibition, 
can be conceived more superb than the intricate and combined 
actions that must take place during our most common move- 
ments. Look at a person running or leaping, or watch the 
motions of the eye. How rapid, how delicate, how compli- 
cated, and yet how accurate, are the motions required ! 
Think of the endurance of such a muscle as the heart, that 
can contract, with a force equal to sixty pounds, seventy-five 
times every minute, for eighty years together, without being 



Note. It would be a profitable exercise for pupils to press their 
fingers upon prominent muscles, and, at the same time, vigorously 
contract them, not only to learn their situations, but their use; as 
the one that bends the arm, 14, fig. 46. 

How is this illustrated? 172. Do all joints require the same number of 
muscles, when called into action ? How many are called into action in the 
movement of the elbow ? "What is their office ? What is said of the 
movement of the ball and socket joint ? 



82 ANATOMY, PHYSIOLOGY, AND HYGIENE. 

Piff. 46. 




PHYSIOLOGY OF THE MUSCLES. 
Fig. 47. 



83 




84 ANATOMY, PHYSIOLOGY, AND HYGIENE. 

Fig. 46. An anterior view of the muscles of the body. 1, The frontal swell of 
the occipito-frontalis. 2, The orbicularis palpebrarum. 3, The levator labii superioris. 
4, The zygomaticus major. 5, The zygomaticus minor. 6, The masseter. 7, The 
orbicularis oris. 8, The depressor labii inferioris. 9. Theplatysma myodes. 10, The 
deltoid. 11, The pectoralis major. 12, The latissimus dorsi. 14, The biceps flexor 
cubiti. 15, The triceps extensor cubiti. 16, The supinator radii longus. 18, The 
flexor carpi radialis longior. 19, The flexor communis digitorum. 20, The annular 
ligament. 21, The palmar fascia. 22, The obliquus externus abdominis. 26, The 
psoas magnus. 27, The adductor longus. 28, The sartorius. 29, The rectus 
femoris. 30, The vastus externus. 31, The vastus internus. 32, The tendon patellce. 
33, The gastrocnemius. 34, The tibialis anticus. 36, The tendons of the extensor 
digitorum communis. 

Fig. 47. A posterior view of the muscles of the body. 3, The complexus. 4, The 
splenius. 5, The masseter. 6, The sterno-cleido mastoideus. 7, The trapezius. 
8, The deltoid. 10, The triceps extensor. 13, The tendinous portion of the triceps. 
14, The anterior edge of the triceps. 15, The supinator radii longus. 17, The 
extensor communis digitorum. 18, The extensor ossis metacarpi pollicis. 19, The 
tendons of the extensor communis digitorum. 20, The olecranon process of the ulna 
and insertion of the triceps. 21, The extensor carpi ulnaris. 22, The extensor com- 
munis digitorum. 24, The latissimus dorsi. 25, Its tendinous origin. 26, The 
obliquus externus. 27, The gluteus medius. 28, The gluteus magnus. 29, The 
biceps flexor cruris. 30, The semi-tendinosus. 31,32, The gastrocnemius. 33, The 
tendo Achillis. 

Practical Explanation. The muscle 1, fig. 46, by its contraction, raises the eyebrows. 
The muscle 2, fig. 46, closes the eyelids. The muscle 3, fig. 46, elevates the upper lip. 
The muscles 4, 5, fig. 46, elevate the angles of the mouth. The muscles 6, fig. 46, 
and 5, fig. 47, bring the teeth together. The muscle 7, fig. 46, closes the mouth. The 
muscle 8, fig. 46, depresses the lower lip. The muscles 9, fig. 46, and 6, fig. 47, bend 
the neck forward. The muscles 3, 4, fig. 47, elevate the head and chin. The muscle 
22, fig. 46, bends the body forward, and draws the ribs downward. The muscle 11, 
fig. 46, brings the shoulder forward. The muscle 7, fig. 47, draws the shoulder 
back. The muscles 10, fig. 46, and 8, fig. 47, elevate the arm. The muscles 11, 
fig. 46, and 24, fig. 47, bring the arm to the side. The muscle 14, fig. 46, bends 
the arm at the elbow. The muscle 10, fig. 47, extends the arm at the elbow. The 
muscles 16, 18, fig. 46, bend the wrist and fingers. The muscle 19 bends the fingers. 
The muscles 18, 21,23, fig. 47, extend the wrist. The muscle 23, fig. 47, extends the 
fingers. The muscles 26, 27, 28, fig. 46, bend the lower limbs on the body, at the hip. 
The muscle 28, fig. 46, draws one leg over the other, (the position of a tailor when 
sewing.) The muscles 27, 28, fig. 47, extend the lower limbs on the body, at the hip. 
The muscles 29, 30, 31 , fig. 46, extend the leg at the knee. The muscles 29, 30, fig. 47, 
bend the leg at the knee. The muscles 34, 36, fig. 46, bend the foot at the ankle, and 
extend the toes. The muscles 31, 32, 33, fig. 47, extend the foot at the ankle. 

Note. Let the anatomy and physiology of the muscular system be reviewed, in 
form of topics, from figs. 46, 47, or from the anatomical outline plates No. 3 and 4. 



HYGIENE OF THE MUSCLES. 85 

CHAPTER X. 

HYGIENE OE THE MUSCLES. 

173. The muscles should be used, in order that the size and 
strength of these organs may be adequate to the demand made 
upon them. It is a law of the system that the action and 
power of an organ are commensurate, to a certain extent, with 
the demand made upon it ; and it is a law of the muscular 
system that, whenever a muscle is called into frequent use, its 
fibres increase in thickness within certain limits, and become 
capable of acting with greater force ; while, on the contrary, 
the muscle that is little used decreases in size and power. 

Illustrations. 1st. The blacksmith uses and rests the mus- 
cles of his arm when striking upon the anvil. They not only 
increase in size, but become very firm and hard. 

2d. The student uses the muscles of the arm but little, in 
holding his books and pen ; they not only become small, 
but soft. 

3d. Let the student leave his books, and wield an iron 
sledge, and the muscles of his arm will increase in size and 
firmness. On the other hand, let the blacksmith assume the 
student's vocation, and the muscles of his arm will become 
soft and less firm. 

174. When the muscles are called into action, the flow of 
blood in the arteries and veins is increased. The increased 
flow of blood in the arteries and veins, causes a more rapid 
deposition of the particles of matter of which the muscles are 

173 — 211. Give the hygiene of the muscles. 173. "What is necessary that 
muscles may attain size and strength ? Give a law of the muscular system. 
Show this by practical illustrations. 174. Why do muscles increase in size 
when exercised ? 

8 



Ob § ANATOMY, PHYSIOLOGY, AND HYGIENE. 

composed. If the exercise is adequate to the power of the 
system, the deposit of new material will exceed in quantity 
the particles of matter removed, and both the size and energy 
of the muscles are increased. But there is a limit to the 
muscles becoming strong by labor. Sooner or later, man will 
attain his growth or power ; yet by judicious exercise, care, 
and discreet management, the greatest power of the muscles 
may be preserved until advanced age. 

175. The muscles are lessened in size and diminished in 
poiver when the exercise is continued so as to produce a feel- 
ing of exhaustion. The loss of material, in this instance, will 
exceed the deposition of the atoms of matter. This is seen 
in the attenuated frames of over-tasked domestic animals, as 
the horse. The same truth is illustrated by the laborious 
agriculturist, who, in consequence of too severe toil while 
gathering the products of the field, frequently diminishes his 
weight several pounds in a few weeks. Exercise, either for 
pleasure or profit, may fatigue, yet it should never be pro- 
tracted to languor or exhaustion, if the individual desires " a 
green old age." 

176. The same amount of exercise will not conduce to the 
health of all individuals. If riding or walking one mile 
causes slight fatigue, this may be beneficial ; while, by trav- 
elling two miles, the exhaustion may be highly injurious. 
Exercise and labor should be adapted to the strength of par- 
ticular individuals. How little soever the strength, that must 
be the measure of exertion. Any other rule would be fatal 
to the hopes of invigorating the system, either by exercise 
or labor. 



Is there a limit to the muscles becoming powerful by action ? How may 
the strength of muscles be kept until advanced age ? 175. "What is the 
effect when exercise is continued until there is a feeling of exhaustion ? 
Give a practical illustration. "What rule is mentioned in regard to exer- 
cise ? 176. Can all persons take the same amount of exercise ? What 
rule is given as to the amount of exercise ? 



HYGIENE OF THE MUSCLES. 87 

177. Relaxation must follow contraction, or, in other words, 
rest must follow exercise. The necessity of relaxation, when 
a muscle has been called into action, is seen in the example 
of a boy extending his arm with a book in his hand, as a 
penalty. The boy can keep the arm extended but a short 
time, make what effort he may. It is also seen in the rest- 
lessness and feverish excitement that are evinced by per- 
sons gazing on troops during days of review. The same is 
noted in shopping. Such employments call into action the 
muscles that support the spinal column in an erect position, 
and the languor or uneasiness is muscular pain. The long- 
continued tension of a muscle enfeebles its action, and event- 
ually destroys its contractility. 

178. In school, the small children, after sitting a short 
time, become restless. If their position be changed, their im- 
perfectly developed muscles will acquire tone, and will again 
support the spinal column erect without pain. The necessity 
for frequent recesses in school, is founded on the organic law 
of muscular action alternating with rest. The younger and 
feebler pupils are, the greater the necessity for frequent 
recesses. We would not have the teacher think that one half 
of the time should be spent in recesses ; or the mother, that 
her daughter is going to school to play. But we do maintain 
that recesses should be given, and that they should be short 
and frequent, especially for small and feeble scholars. 

179. Exhaustion is the inevitable result of continued mus- 
cular contraction. For example, let a lady ply the needle 
quickly for some hours, and the muscles of the back and 
right arm will become exhausted, which will be indicated by 
a sense of weariness in these parts. A change of employ - 

177. "What is said of the contraction and relaxation of the muscles ? Give 
examples of the necessity of relaxing the muscles. 178. Why should not 
small children be confined in one position for a long time ? What evils 
result from this practice ? What class of pupils should have recesses most 
frequently. 179. What effect has continued muscular contraction ? 



88 ANATOMY, PHYSIOLOGY, AND HYGIENE. 

merit and position calls into action a different set of muscles, 
and the exhausted organs are relieved. 

180. Much more labor will be accomplished by taking time 
to relax the exhausted muscles, or by so changing the employ- 
ment as to bring into action a new set of muscles ; the wood- 
man thus relieves himself, by sawing and splitting alternately. 
This principle applies to the labor of the horse and ox ; and 
it is also applicable to all kinds of employment. With the 
invalid convalescing from fever, relapses result from inatten- 
tion to these laws. When a patient is recovering from sick- 
ness, his physician should take care that his exercise be 
proper, neither too much, too little, nor too long continued. 

181. The muscles of growing youths will not endure so 
much exercise or labor as those of mature men. In youth a 
portion of the vital, or nervous energy of the system, is 
expended upon the growth of the organs of the body, while 
in the individual who has attained his growth, this expendi- 
ture is not demanded ; consequently severe labor or exercise 
should not be imposed on growing children. 

Observation. In the campaigns of Napoleon Bonaparte, 
his army was frequently recruited by mere boys. He com- 
plained to the French government, because he was not supplied 
with men of mature years, as the youths could not endure the 
exertion of his forced marches. 

182. The muscles should be gradually called into action. 
These organs in action require more blood and nervous fluid 
than when at rest. As the circulation of these fluids can only 
be increased in a gradual manner, it follows, that, when the 
muscular system has been in a state of rest, it should not sud- 
denly be called into vigorous action. On arising from a bed, 
lounge, or chair, the first movements of the limbs should be 
slow, and then gradually increased. 

Observation. If a man has a certain amount of work to 

180. How can the greatest amount of labor be secured with the least 
exhaustion to the muscles ? 181. Why should not severe labor be imposed 
on growing children ? 182. How should the muscles be called into action ? 



HYGIENE OF THE MUSCLES. 89 

perform in nine hours, and his muscles have been in a state 
of rest, he will do it with less fatigue by performing half the 
amount of the labor in five hours, and the remainder in four 
hours. The same principle should be regarded in driving 
horses and other beasts of burden. 

183. The muscles should he rested gradually, when they 
have been vigorously used. If a person has been making great 
muscular exertion in cutting wood, or any other employment, 
instead of sitting down to rest, he should continue muscular 
action, for a short time, by some moderate labor or amusement. 

184. If the system has been heated by muscular action, and 
the skin is covered with perspiration, avoid sitting down " to 
cool " in a current of air ; rather, put on more clothing, 
and continue to exercise' moderately. In instances when 
severe action of the muscles has been endured, bathing and 
rubbing the skin of the limbs and joints that have been used, 
are of much importance. The laboring agriculturist and 
industrious mechanic, by reducing to practice this suggestion, 
would thus prevent soreness of the muscles, and stiffness of 
the joints. 

185. The muscles should be abundantly supplied with pure 
blood. This state of the circulating fluid requires a healthy 
condition of the digestive apparatus, and that the skin should 
be kept warm by proper clothing, clean by bathing, and be 
acted upon by pure air and good light ; the movements 
of the ribs and diaphragm should be unrestricted, and the 
lungs should have ample volume and be supplied with pure 
air. In all instances, muscular power is greatest when the 
preceding conditions exist, as the muscles are then stimulated 
by pure blood ; consequently, it is of practical importance to 

183. How should the muscles be rested when they have been vigorously- 
used ? 184. What precaution is given when the skin is covered with per- 
spiration ? How may soreness of the muscles, consequent upon severe 
action, be prevented ? 185. Should the muscles be supplied Avith pure 
blood ? "When is muscular power the greatest ? 
8* 



90 ANATOMY, PHYSIOLOGY, AND HYGIENE. 

the mechanic, the farmer, the man of leisure, and not less so 
to the ladies, to observe these conditions, whatever vocation of 
life they pursue. 

186. The muscles should be used in pure air. The purer 
the air we breathe, the more stimulating the blood supplied to 
the muscles, and the longer they can be used in labor, walk- 
ing, or sitting, without fatigue and injury ; hence the benefit 
derived in thoroughly ventilating all inhabited rooms. For the 
same reason, if the air of the sick-room is pure, the patient 
will sit up longer than when the air is impure. 

Observation. It is a common remark that sick persons will 
sit up longer when riding in a carriage, than in an easy chair 
in the room where they have lain sick. In the one instance, 
they breathe pure air ; in the other, usually, a confined, im- 
pure air. 

187. The muscles should be exercised in the light. Light, 
particularly that of the sun, exercises as great an influence 
on man and the inferior animals as it does on plants. Both 
require the stimulus of this agent. Shops occupied by me- 
chanics, kitchens, and sitting-rooms, should be well lighted, 
and situated on the sunny side of the house. Cellar kitchens 
and underground shops should be avoided. For similar 
reasons, students should take their exercise during the day, 
rather than in the evening, and, as much as possible, laborers 
should avoid night toil. 

Illustrations. Plants that grow in the shade, as under 
trees, or in a dark cellar, are of lighter color and feebler 
than those that are exposed to the light of the sun. Persons 
that dwell in dark rooms are paler and less vigorous than 
those who inhabit apartments well lighted, and exposed to the 
rays of the sun. 

186. Why should the muscles be used in pure air ? Give a common 
observation. 187. What effect has light on the muscular system ? "What 
should the laborer avoid ? Why should not students take their daily exer- 
cise in the evening ? How is the influence of solar light illustrated ? 



HYGIENE OF THE MUSCLES. 91 

188. 'Exercise should he regular and frequent. The sys- 
tem needs this means of invigoration as regularly as it does 
new supplies of food. It is no more correct that we devote 
several days to a proper action of the muscles, and then 
spend one day inactively, than it is to take a proper amount 
of food for several days, and then withdraw this supply for 
a day. The industrious mechanic and the studious minister 
surfer as surely from undue confinement as the improvident 
and indolent. The evil consequences of neglect of exercise 
are gradual, and steal slowly upon an individual. But sooner 
or later they are manifested in muscular weakness, dyspepsia, 
and nervous irritability. 

Observation. The custom among farmers of enduring 
severe and undue toil for several successive days, and then 
spending one or two days in idleness to rest, is injudicious. 
It would be far better to do less in a day, and continue the 
labor through the period devoted to idleness, and then no rest 
will be demanded. 

189. Every part of the muscular system should have its 
appropriate share of exercise. Some employments call into 
exercise the muscles of the upper limbs, as shoe-making ; 
others, the muscles of the lower limbs ; while some, the mus- 
cles of both upper and lower limbs, with those of the trunk, 
as farming. In some kinds of exercise, the lower limbs are 
mainly used, as in walking ; in others, the upper limbs ; and 
again, the muscles of the trunk, together with those of the 
upper and lower limbs, as in archery, quoits, playing ball. 
Those trades and kinds of exercise are most salutary, in 
which all the muscles have their due proportion of action, 

188. How should exercise be taken ? What is said respecting irregular 
exercise ? Are the consequences of neglected exercise immediately appa- 
rent ? "What practical observation is given ? 189. Should every muscle 
have its due amount of exercise ? Mention some employments that only 
call into action the muscles of the upper limbs. Those of the lower limbs. 
Those of the trunk and limbs. Mention, in the different pastimes, what 
muscles are called into action. 



92 ANATOMY, PHYSIOLOGY, AND HYGIENE. 

as this tends to develop and strengthen them equally. Thus 
labor upon the farm and domestic employment are superior 
as vocations, and archery, quoits, and dancing, if the air is 
pure, among the pastimes. For sedentary persons, that kind 
of exercise is best which calls into action the greatest number 
of muscles. 

190. The proper time for labor or exercise should be ob- 
served. This is modified by many circumstances. As a 
general rule, the morning, when the air is pure and the ground 
dry, is better than the evening ; for then, the powers of the 
body are greatest. Severe exercise and labor should be 
avoided immediately before or after eating a full meal, for 
the energies of the system are then required to perform the 
digestive function. For similar reasons, it is not an appro- 
priate time for energetic muscular action immediately before 
or after severe mental toil, as the powers of the system are 
then concentrated upon the brain.* 

191. The muscles require sleep to restore their expended 
energies. Among the arrangements of creative wisdom, no 
one harmonizes with the wants of the system more than the 
alternation of day and night. The natural inclination of man 
to sleep, is in the stilly hour of night, when all nature reposes, 
and to be in action during the light of day. An inversion of 
this law of rest causes greater exhaustion of the system than 



* It appears to be a fact, that no two important organs can be 
called into intense action at the same time, without injury to both, 
as well as to the general system. This arises from the circumstance 
that an organ, when in functional action, attracts fluids (sanguineous 
and nervous) from other organs of the system. Except in a few 
instances of high health in youth, the power of the system is not 
adequate to supply more than one organ in action with the appro- 
priate fluids at the same time. 

What kinds of exercise are best ? 190. What rule is given respecting 
the time for exercise ? 191. Why do the muscles require sleep ? What is 
the effect of an inversion of the law of rest ? 



HYGIENE OF THE MUSCLES. 93 

the same amount of exertion during daylight. This is illus- 
trated by the wearied and exhausted condition of watchers, 
night-police, and other individuals who spend a part of the 
night in some active business of life. 

192. The muscles should not he compressed. Compression 
prevents the blood from passing to the muscles with freedom ; 
consequently, they are not supplied with material to renovate 
and promote their growth. Again, pressure stimulates the 
lymphatics to action ; and by the increased activity of these 
vessels the muscles are attenuated. In the case of a man with 
a fractured limb, the muscles are not only enfeebled by inac- 
tion, but diminished in size by compression from the dressing. 
Limbs enfeebled in this way will not recover their size, tone, 
and strength, until the bandages are removed, and a proper 
amount of exercise taken. 

193. The pressure of tight dresses, under the name of a 
" snug fit," enfeebles the muscles of the back, and is a com- 
mon cause of projecting shoulders and curvature of the spinal 
column. Thus every appendage to the dress of ladies which 
prevents free motion of the muscles of the chest and spinal 
column, weakens the muscles thus restrained, and not only 
prevents the proper expansion of the lungs, but, by weakening 
the muscles which sustain the spine, induces curvature and 
disease. Whalebone, wood, steel, and every other unyielding 
substance, should be banished from the toilet, as enemies of 
the human race. 

194. The mind exerts a great influence upon the tone and 
contractile energy of the muscular system. A person acting 
under a healthy mental stimulus will make exertion with less 
fatigue than he would without this incentive. For this reason, 

a sportsman will pursue his game miles without fatigue, while 

* 

192. Why should not the muscles be compressed ? 193. What is the 
effect of tight clothing upon the muscles ? 194. What is said of the influ- 
ence of the mind upon muscular activity ? Give an illustration of mental 
stimulus cooperating with muscular activity in the case of a sportsman. 



94 



ANATOMY, PHYSIOLOGY, AND HYGIENE. 



his attendant, not having any mental stimulus, will become 
weary. Again, if the sportsman spends some hours in 
pursuit of his favorite game without success, a feeling of 
languor creeps over him ; but while he is thus fatigued and 
dispirited, let him catch a glimpse of the game, — his wearied 
feelings are immediately dissipated, and he presses on with 
renewed energy and recruited strength. 

195. This principle was well illustrated in the retreat from 
Russia of the defeated and dispirited French army. When no 
enemy was near, they had hardly strength sufficient to carry 
their arms ; but no sooner did they hear the report of the 
Russian guns, than new life seemed to pervade them, and they 
wielded their weapons powerfully until the foe was repulsed ; 
then there was a relapse to weakness, and prostration followed. 
It is thus with the invalid when riding for his health ; — relate 
an anecdote, or excite this mental stimulus by agreeable con- 
versation, and much benefit will accrue from the ride to the 
debilitated person. So it is in the daily vocations of life ; if 
the mind have some incentive, the tiresomeness of labor will 
be greatly diminished. Let an air of cheerfulness ever per- 
vade our every employment, and, like music, " it sweetens 
toil." 

196. Facts illustrative of the inutility of calling the muscles 
into action, without the cooperation of the mind, are seen in 
the spiritless aspect of many of our boarding school proces- 
sions, when a walk is taken merely for exercise, without 
having in view any attainable object. But present to the 
mind a botanical or geological excursion, and the saunter 
will be exchanged for the elastic step, the inanimate appear- 
ance for the bright eye and glowing cheek. The difference 

195. Give an illustration of mental stimulus cooperating with muscular 
activity in the case of the dispirited French army in their retreat from 
Russia. How can a union of mental impulse and muscular action be ben- 
eficial to an invalid ? Does this same principle apply to those who labor ? 
196. Give an instance of the different effects produced by the absence and 
presence of the mental stimulus. 



HYGIENE OF THE MUSCLES. 95 

is, simply, that, in the former case, the muscles are obliged to 
work without that full nervous impulse so essential to their 
energetic action ; and that, in the latter, the nervous influence 
is in full and harmonious operation. 

197. It must not, however, be supposed that a walk sim- 
ply for the sake of exercise can never be beneficial. Every 
one, unless prevented by disease, should consider it a duty to 
take exercise every day in the open air ; if possible, let it be 
had in combination with harmonious mental exhilaration ; if 
not, let a walk, in an erect position, be made so brisk as to 
produce rapid respiration and circulation of the blood, and in 
a dress that shall not interfere with free motions of the arms 
and free expansion of the chest. 

Observation. The advantages of combining harmonious 

mental excitement, with muscular activity, is thus given by 

Dr. Armstrong : — 

" In ichate'er you sweat, 
Indulge your taste. Some love the manly toils, 
The tennis some, and some the graceful dance ; 
Others, more hardy, range the purple heath 
Or naked stubble, where, from field to field, 
The sounding covies urge their lab'ring flight, 
Eager amid the rising cloud to pour 
The gun's unerring thunder ; and there are 
"Whom still the mead of the green archer charm. 
He chooses best whose labor entertains 
His vacant fancy most ; the toil you hate 
Fatigues you soon, and scarce improves your limbs." 



197. May not a walk, simply as an exercise, be beneficial ? "What is 
preferred ? 



96 ANATOMY, PHYSIOLOGY, AND HYGIENE. 

CHAPTER XI. 

HYGIENE OF THE MUSCLES, CONTINUED. 

198. The erect attitude lessens the exhaustion of the muscles. 
A person whose position is erect will stand longer, walk further, 
and perform more labor, than an individual whose position is 
stooping, but equal in all other respects. The manly port in 
an erect attitude, depends chiefly upon the action of the mus- 
cles of the back ; and it follows that the fewer the muscles in 
a state of tension, the less the draught upon the nervous sys- 
tem, and the less its exhaustion. Another advantage which 
attends the erect position is, the trunk and head are balanced 
upon the bones and cartilages of the spinal column. If the 
body slightly incline forward, the muscles attached to the 
posterior side of the spine, by a gentle contraction, will bring 
it to the perpendicular, and even incline it backward. This 
is immediately removed by a slight contraction of the muscles 
upon the anterior side of the spinal column. 

199. In the erect position, there is a constant slight oscil- 
lation of the body backward and forward, like the movement 
of a pendulum ; while, in the stooping posture, the muscles 
on the posterior side of the spinal column are kept in a state 
of continued tension and contraction, to prevent the body from 
falling forward. This enfeebles the muscles of the back, and 
exhausts the nervous energy, while the erect position favors 
their development and power, because there is an alternate 
contraction and relaxation of the muscles. Again, in the 
stooping position, The lower limbs are curved at the knee. In 

198. Why will a person who stands erect walk further, and perform more 
labor, than if he assumed the stooping posture ? 199. Why are the muscles 
of the back so soon exhausted in the stooping position ? 



HYGIENE OF THE MUSCLES. 



97 



this attitude, there is a constant tension of the muscles of the 
lower extremities, which produces muscular exhaustion. 



Fiar. 48. 



Fig. 49. 




Fig. 48. 1, A perpendicular line from the centre of the feet to the upper extremity 
of the spinal column, where the head rests. 2, 2, 2, The spinal column, with its three 
natural curves. Here the head and body are balanced upon the spinal column and 
joints of the lower extremities, so that the muscles are not kept in a state of tension. 
This erect position of the body and head is always accompanied with straight lower 
limbs. 

Fig. 49. 1, A perpendicular line from the centre of the feet. 2, Represents the 
unnatural curved spinal column, and its relative position to the perpendicular, (1.) 
The lower limbs are curved at the knee, and the body is stooping forward. While 
standing in this position, the muscles of the lower limbs and back are in continued 
tension, which exhausts and weakens them. 



What is represented by figs. 48 and 49 ? 

9 



98 ANATOMY, PHYSIOLOGY, AND HYGIENE. 

200. When it is necessary to call into action a part of the 
muscles of the system in the performance of any duty, as 
those of the lower limbs in walking, if the muscles of other 
parts are in a state of inaction, the influence of the nervous 
system can be determined in an undivided manner upon those 
parts of the lower limbs in action ; hence they will not so soon 
become wearied or exhausted, as when this influence is divided 
between a greater number of muscles. In performing any 
labor, as in speaking, reading, singing, mowing, sewing, &c, 
there will be less exhaustion, and the effort can be longer 
maintained in the erect position of the body and head, than in 
a stooping attitude. 

Experiment. Hold in each hand a pail of water or equal 
weights, in a stooping posture, as long as it can be done 
without much suffering and injury. Again, when the mus- 
cular pain has ceased, hold the same pails of water, for the 
same length of time, in an erect posture, and note the differ- 
ence in the fatigue of the muscles. 

201. If the stooping posture is acquired in youth, we are 
quite certain of seeing the deformed shoulders in old age. 
Hence the importance of duly exercising the muscles of the 
back, for when they are properly developed, the child can and 
will stand erect. In this attitude, the shoulders will be thrown 
back, and the chest will become broad and full. 

202. Pupils, while standing during recitations, often inad- 
vertently assume the attitude represented by fig. 49, and it is 
the duty of teachers to correct this position when assumed. 
When a child or adult has contracted a habit of stooping, and 
has become round-shouldered, it can be measurably, and gen- 
erally, wholly, remedied by moderate and repeated efforts to 
bring the shoulders back, and the spinal column in an erect 

200. What suggestion when it is necessary to call into action a part of 
the muscular system ? Give the experiment that illustrates this principle. 
231. Why should a child be taught to stand erect ? 202. How can round 
shoulders acquired by habit be remedied ? 



HYGIENE OF THE MUSCLES. 



99 



position. This deformity can and should be remedied in our 
schools. It may take months to accomplish the desired end, 
yet it can be done as well under the direction of the kind 
instructor, as under the stern, military drill sergeant, who never 
fails to correct this deformity among his raw recruits. 



Fig. 50. 




Fig. 50. A proper position in sitting. 

203. The child should he taught to sit erect lohen employed 
in study or work. This attitude favors a healthy action of the 
various organs of the system, and conduces to beauty and 
symmetry of form. Scholars are more or less inclined to lean 
forward and place the elbow on the table or desk, for support ; 

203. Why should the erect attitude be assumed in sitting ? 



100 



ANATOMY, PHYSIOLOGY, AND HYGIENE. 



and this is often done when their seats are provided with 
backs. Where there is a predisposition to curvature of the 
spine, no position is more unfavorable or more productive of 
deformities than this ; for it is usually continued in one direc- 
tion, and the apparent deformity it induces is a projection of 
the shoulders. If the girl is so feeble that she cannot sit 

Fig. 51. 




Fig. 51. An improper position in sitting 



erect, as represented by fig. 50, let her stand or recline on a 
couch ; either is preferable to the position represented by fig. 
51. In furnishing school-rooms, care should be taken that 
the desks are not so low as to compel the pupils to lean 
forward in examining their books. 



HYGIENE OF THE MUSCLES. 101 

204. The muscles, iche?i exhausted, cannot endure continued 
effort. When the energies of the muscular system have been 
expended by severe and long-contin.ued exercise, or the brain 
and nervous system prostrated by protracted mental effort, the 
muscles are unfitted to maintain the body erect in standing or 
sitting for a long time, as the nervous system, in its exhausted 
state, cannot supply a sufficient amount of its peculiar influ- 
ence to maintain the supporting muscles of the body and head 
in a state of contraction. Hence, a child or adult, when much 
fatigued, should not be compelled to stand or sit erect in one 
posture, but should" be permitted to vary the position fre- 
quently, as this rests and recruits both the muscular and the 
nervous system. 

205. A slight relaxation of the muscles tends to prevent 
their exhaustion. In walking, dancing, and most of the 
mechanical employments, there will be less fatigue, and the 
movements will be more graceful, when the muscles are 
slightly relaxed. When riding in cars or coaches, the system 
does not suffer so severely from the jar if there is a slight 
relaxation of the muscles, as when they are in a state of rigid 
contraction. 

Experiments. Attempt to bow with the muscles of the 
limbs and trunk rigid, and there will be a stiff bending of the 
body only at the hip-joint. On the other hand, attempt to bow 
with the muscles moderately relaxed ; the ankle, the knee, 
and the hip-joint will slightly bend, accompanied with an easy 
and graceful curve of the body. 

206. The muscles when relaxed, together with the yielding 
character of the cartilage, and the porous structure of the ends 
of the bones that form a joint, diffuse or deaden the force of 

204. When are the muscles unfitted to maintain the system erect either 
in standing or sitting ? What is necessary when this condition of the 
system exists ? 205. Why should the muscular system be slightly relaxed 
in -walking, &c. ? Give illustrative experiments. 206. What is the reason 
that we do not feel the jar in falling from a moderate height ? 

9* 



102 ANATOMY, PHYSIOLOGY, AND HYGIENE. 

jars, or shocks, in stepping suddenly down stairs, or in fall- 
ing from moderate heights. Hence, in jumping or falling 
from a carriage, or any height, the shock to the organs of 
the system may be obviated in the three following ways : 
1st. Let the muscles be relaxed, not rigid. 2d. Let the 
limbs be bent at the ankle, knee, and hips ; the head should 
be thrown slightly forward, with the trunk a little stooping. 
3d. Fall upon the toes, not the heel. 

Experiments. Stand with the trunk and lower limbs firm, 
and the muscles rigid ; then jump a few inches perpendic- 
ularly to the floor, and fall upon the heels. Again, slightly 
bend the limbs, jump a few inches, and fall upon the toes, and 
the difference in the force of the shock, to the brain and other 
organs, will be readily noticed. 

207. The muscles require to be educated, or trained. The 
power of giving different intonations in reading, speaking, sing- 
ing, the varied and rapid executions in penmanship, and all 
mechanical or agricultural employments, depend, in a measure, 
upon the education of the muscles. In the first effort of mus- 
cular education, the contractions of the muscular fibres are 
irregular and feeble, as may be seen when the child begins to 
walk, or in the first efforts of penmanship. 

208. Repetition of muscular action is necessary. To render 
the action of the muscles complete and effective, they must 
be called into action repeatedly and at proper intervals. This 
education must be continued until not only each muscle, but 
every fibre of the muscle, is fully under the control of the 
will. In this way persons become skilful in every employ- 
ment. In training the muscles for effective action, it is very 
important that correct movements be adopted at the com- 

How is this shown by experiment ? 207. Upon what do the different 
intonations of sound or mechanical employments depend ? "Why are the 
first efforts in educating the muscles indifferent or irregular ? 208. Why 
is repetition of muscular action necessary ? Why is it important that 
correct movements be adopted in the first efforts of muscular education ? 



HYGIENE OF THE MUSCLES. 



103 



mencement. If this is neglected, the motions will be con- 
strained and improper, while power and skill will be lost. 

Illustration. If a boy, while learning to mow, is allowed 
to swing his scythe in a stooping position, twisting his body at 
every sweep of the scythe, he will never become an easy, 
efficient mower. Proper instruction is as necessary in many 
of the agricultural branches as in the varied mechanical 
employments. 



Fig. 52. 



Fig. 53. 




Fig. 52. An improper, but not an unusual position, when writing. 
Fig. 53. A proper position, when writing. 

209. Good penmanship requires properly trained muscles. 
To a deficient analysis of the movements of the arm, hand, 
and fingers, on the part of teachers and pupils in penman- 
ship, together with an improper position in sitting, is to be 

How is this illustrated? 209. Why have so many pupils failed in 
acquiring good penmanship ? 



104 ANATOMY, PHYSIOLOGY, AND HYGIENE. 

ascribed the great want of success in acquiring this art. The 
pen should be held loosely, and when the proper position is 
attained, the scholar should make an effort to imitate some 
definite copy as nearly as possible. The movements of the 
fingers, hand, and arm, necessary to accomplish this, should 
be made with ease and rapidity, striving, at each effort, to 
imitate the copy more nearly. 

210. When the arm, hand, and fingers are rigid, the large 
muscles, that bend and extend these parts, are called into too 
intense action. This requires of the small muscles, that pro- 
duce the lateral movements, which are essential to rapidity in 
writing, an effort which they cannot make, or can with diffi- 
culty accomplish. 

Experiment. Vigorously extend the fingers by a violent 
and rigid contraction of the muscles upon the lower part of 
the arm, and the lateral movement which is seen in their sep- 
aration cannot be made. But gently extend the fingers, and 
their oblique movements are made with freedom. 

211. An individual who is acquainted with the laws of 
health, whose muscles are well trained, will perform a certain 
amount of labor with less fatigue and waste to the system, 
than one who is ignorant of the principles of hygiene, and 
whose muscles are imperfectly trained. Hence the laboring 
poor have a deep interest in acquiring a knowledge of prac- 
tical physiology, as well as skill in their trade or vocation. It 
is emphatically true to those who earn their bread by the 
" sweat of their brow," that " knowledge is power." 

210. What is said of the lateral and oblique movements of the arm, 
hand, and fingers in writing ? How is this shown by experiment ? 211. "Why 
is the study of physiology and hygiene of utility to the laborer ? 



ANATOMY OF THE TEETH. 105 



CHAPTER XII. 

THE TEETH. 

212. The teeth, in. composition, nutrition, and growth, 
are different from other bones of the body. They vary in 
number at different periods of life, and, unlike other bones, 
they are exposed to the immediate action of atmospheric air 
and foreign substances. The bones of the system, generally, 
when fractured, unite ; but there is never a permanent union 
of a tooth when broken. 

ANATOMY OF THE TEETH. 

213. The teeth are attached to the upper ana lower jaw- 
bone, by means of bony sockets, called al've-o-lar processes. 
These give great solidity to the attachment of the teeth, and 
frequently render their extraction difficult. The gums, by 
their fibrous, fleshy structure, serve to fix the teeth more 
firmly in the jaw. 

Observation. When a permanent tooth is extracted, these 
bony processes are gradually absorbed, so that in advanced 
age there remains only the jaw-bone covered by the lining 
membrane of the gum. This accounts for the narrow jaw 
and falling in of the lips in old age. Frequently, a piece of 
the alveolar process comes out with the tooth when extracted, 
and the dentist has then the credit of " breaking the jaw." 

212. What is said of the teeth ? In what respect do they differ from other 
bones of the body ? 213—218. Give the anatomy of the teeth. 213. What 
confines the teeth in the jaw-bone ? What becomes of the socket when a 
tooth is removed ? What effect has this absorption upon the jaw and 
lips ? 



106 ANATOMY, PHYSIOLOGY, AND HYGIENE. 

No great injury results from the removal of the process in this 
manner. 

214. The teeth are formed in the interior of the jaws, and 
within dent'al capsules, (membranous pouches,) which are 
enclosed within the substance of the bone, and present in 
their interior a fleshy bud, or granule, from the surface of 
which exudes the ivory, or the bony part of the tooth. In 
proportion as the tooth is formed, it rises in the socket, which 
is developed simultaneously with the tooth, and passes through 
the gum, and shows itself without. 

Fig. 54. 




Fig. 54. 1, The body of the lower jaw. 2, Ramus, or branch of the jaw, to which 
the muscles that move it are attached. 3, 3, The processes which unite the lower 
jaw with the head, i, The middle and lateral incisor tooth of one side. '6, The 
bicuspid teeth, c, The cuspids, or eye teeth, m, The three molar teeth. A, shows 
the relation of the permanent to the temporary teeth. 

215. The first set, which appears in infancy, is called 
tem'po-ra-ry, or milk teeth. They are twenty in number ; ten 
in each jaw. Between six and fourteen years of age, the tem- 
porary teeth are removed, and the second set appears, called 
per'ma-nent teeth. They number thirty-two, sixteen in each 
jaw. 

214. "Where and how are the teeth formed ? Explain fig. 54. 215. What 
are the first set called ? How many in each jaw ? The second set ? How 
many in number ? 



ANATOMY OF THE TEETH. 



107 



216. The four front teeth in each jaw are called in-ci'sors, 
(cutting teeth ;) the next tooth in each side, the cus'pid, (eye 
tooth ;) the next two, bi-cus'pids, (small grinders ;) the next 
two, molars, (grinders.) The last one on each side of the 
jaw is called a wisdom tooth, because it does not appear until 
a person is about twenty years old. The incisors, cuspids, 
and bicuspids, have each but one root. The molars of the 
upper jaw have three roots, while those of the lower jaw have 
but two. 

Fisc. 55. 




Fig. 55. The permanent teeth of the upper and lower jaw. a, b, The incisors, 
c, The cuspids, d, e, The bicuspids. /, g, The molars, (double teeth.) h, The wis- 
dom teeth. 

Observation. The shape of the teeth in different species of 
animals is adapted to the kind of food on which they subsist. 
Those animals that feed exclusively on flesh, as the lion, have 
the cuspids, or canine teeth, largely developed, and the molars 
have sharp cutting points. Those animals that feed on grass 
and grain, as the horse and the sheep, have their molar teeth 
more rounded and flat on the crown. The human teeth are 



216. Give the names of the permanent teeth. "What teeth have but one 
root, or "fang" ? How many roots have the molars of the upper jaw? 
Of the lower jaw? "What is said of the shape of the teeth in different 
species of animals ? 



108 



ANATOMY, PHYSIOLOGY, AND HYGIENE. 



adapted to feed on fruits, grain, or flesh, as they are less 
pointed than those of the cat, and more pointed than those of 
the sheep. 

217. The teeth are composed principally of two substances 
— the i'vo-ry and the en-am 1 el. The internal part of the tooth, 
or the ivory, is harder and more enduring than bone, and forms 
the body of the tooth. The enamel is remarkable for its hard- 
ness, and varies somewhat in color with the age, temperament, 
habits, and manner of living of different individuals. When 
any part of the enamel is destroyed, it is never regenerated. 



Fig. 56. 



Fig. 57. 





Fig. 56. A side view of the body and enamel of a front tooth. 

Fig. 57. A side view of a molar tooth. 1, The enamel. 2, The body of the tooth. 
3, The cavity in the crown of the tooth that contains the pulp. 4, A nerve that 
spreads in the pulp of the tooth. 5, An artery that ramifies in the pulp of the tooth. 

218. Each tooth is divided into two parts, namely, crown 
and root. The crown is that part which protrudes from the 
jaw-bone and gum, and is covered by the highly polished 
enamel. The root, or " fang," is placed in the sockets of the 
jaw, and consists of bony matter. Through this bony sub- 
stance several small vessels pass, to aid in the growth and 



217. Give the structure of the teeth. What is said of the enamel ? 
218. Into how many parts are the teeth divided ? Describe the crown. The 
root. What vessels pass through the bony matter ? What is their use ? 



PHYSIOLOGY OF THE TEETH. 109 

also in the removal of the tooth. There are, beside these 
vessels, small white cords passing to each tooth, called nerves. 
(See fig. 57.) When these nerves are diseased, we have the 
toothache. 

PHYSIOLOGY OF THE TEETH. 

219. The use of the teeth is twofold. 1st. By the action 
of the incisors the food is divided, while the molars grind or 
break down the more solid portions of it. By these processes, 
the food is prepared to pass more easily and rapidly into the 
stomach. 

220. In the mastication of food there are two movements 
of the lower jaw — the action by which the teeth are brought 
together, and the lateral motion. In the former, the food is 
cut or divided, the jaws acting like shears. This movement 
is produced by the action of two large muscles situated on 
each side of the head and face. 

Observation. The muscles attached to the lower jaw are of 
great strength ; by their action alone, some persons are ena- 
bled to bite the hardest substances. By putting the fingers 
upon the side of the head above and in front of the ears, and 
upon the face above the angle of the jaw, while masticating 
food, the alternate swelling and relaxation of these muscles 
will be clearly felt. 

221. The lateral, or grinding movement of the teeth, is pro- 
duced by the action of a strong muscle that is attached to the 
lower jaw on the inside. 

Observation. Those animals that live solely on flesh, have 
only the cutting, or shear-like movement of the jaws. Those 



219 — 222. Give the physiology of the teeth. 219. Give one of the functions 
of the teeth. 220. How many movements of the lower jaw in masticating 
food ? "What effect has the first movement upon the food ? How pro- 
duced ? What is the character of the masticating muscles ? 221. How is 
the grinding motion of the teeth produced ? What is said of the move- 
ments of the teeth in different animals ? 

10 



110 ANATOMY, PHYSIOLOGY, AND HYGIENE. 

that use vegetables for food, have the grinding motion ; while 
man has both the cutting and grinding movement. 

222. 2d. The teeth aid us in articulating with distinctness 
certain letters and words. An individual who has lost his 
front teeth cannot enunciate distinctly certain letters called 
dental. Again, as the alveolar processes are removed by- 
absorption soon after the removal of the teeth, the lips and 
cheeks do not retain their former full position, thus marring, in 
no slight degree, the symmetry of the lower part of the face. 
Consequently, those simple observances that tend to the 
preservation of the teeth are of great practical interest to all 
persons. 

HYGIENE OF THE TEETH. 

223. To preserve the teeth, they must be kept clean. After 
eating food, they should be cleansed with a brush and water, 
or rubbed with a piece of soft flannel, to pftvent the tartar 
collecting, and to remove the pieces of food that may have 
lodged between them. Toothpicks may be useful in remov- 
ing any particles inaccessible to the brush. They may be 
made of bone, ivory, or the common goose-quill. Metallic 
toothpicks should not be used, as they injure the enamel. 

224. The mouth should be cleansed with pure tepid water at 
night, as well as in the morning ; after which the teeth should 
be brushed upward and downward, both on the posterior and 
anterior surfaces. It may be beneficial to use refined soap, 
once or twice every week, to remove any corroding substance 
that may exist around the teeth ; care being taken to thor- 
oughly rinse the mouth after its use. 

225. Food or drink should not be taken into the mouth 
when very hot or very cold. Sudden changes of temperature 
will crack the enamel, and finally produce decayed teeth. 

222. What is another use of the teeth? 223—232. Give the hygiene 
of the teeth. 223. How can the teeth be preserved ? By what means ? 
224. How often should they be cleansed ? 225. What is said of very hot 
or cold drinks ? 



HYGIENE OF THE TEETH. Ill 

Observation. On this account, smoking is pernicious, be- 
cause the teeth are subjected to an alternate inhalation of both 
cold and warm air. 

226. The temporary teeth should be removed as soon as 
they become loose. If a permanent tooth makes it appear- 
ance before the first is removed, or has become loose, the 
milk tooth, although not loose, should be removed without 
delay. This is necessary that the second set of teeth may 
present a regular and beautiful appearance. 

227. In general, when the permanent teeth are irregular, 
one or more should be removed. If the teeth are crowded and 
irregular, in consequence of the jaw being narrow and short, 
or when they press so hard upon each other as to injure the 
enamel, remove one or more to prevent their looking unsight- 
ly, and in a few months the remaining teeth, with a little care, 
will fill the spaces. 

Observation. When it is necessary to remove a tooth, apply 
to some skilful operator. It requires as much skill and knowl- 
edge to extract teeth well, as it does to amputate a limb ; yet 
some persons, who possess strong arms, will obtain a pair of 
forceps, or a tooth-key, and hang out the sign of " surgeon- 
dentist," although ignorant of the principles that should guide 
them. 

228. It is not always necessary to have teeth extracted when 
they ache. The nerve, or the investing membrane of the 
root, may be diseased, and the tooth still be sound. In such 
instances, the tooth should not be extracted, but the diseased 
condition may be remedied by proper medication. There are 
many sound teeth, that become painful, as already mentioned, 
which are unnecessarily removed. 



"Why is smoking injurious to the teeth ? 226. "What remark respecting 
the temporary teeth ? 227. "What remarks respecting the permanent 
teeth ? Do those persons that extract teeth require skill as well as knowl- 
edge ? 228. Why should not teeth be extracted at all times when they 
are painful ? 



112 ANATOMY, PHYSIOLOGY, AND HYGIENE. 

Illustration. Dr. H. M., of Belfast, Me., related to me that 
an individual in that vicinity had his teeth, (all of them 
sound,) on one side of the lower jaw, extracted by an igno- 
ramus of a " tooth-puller," and this without any relief from 
pain. The disease was ti£ douloureux, which was relieved 
by Dr. M. 

229. The preservation of the teeth requires that they he 
frequently examined. When a part of the enamel is removed, 
and a small portion of the body of the tooth has become cari- 
ous, in many instances such teeth may be preserved from 
further decay by having them filled or " plugged " with gold 
foil. All amalgams, pastes, and cheap patent articles for 
filling, should be avoided, if you would preserve both the teeth 
and the general health. 

230. The practice of cracking nuts with the teeth, or of 
lifting heavy bodies, and the constant habit of biting thread, 
should be avoided, as they finally destroy the enamel. 

231. All acidulated drinks and mineral waters, that " set 
the teeth on edge" are injurious. All tooth-powders and 
washes that contain any article that is acid, corrosive, or grind- 
ing, should be banished from the toilet. Tobacco is not a pre- 
servative of the teeth. It contains " grit," which wears away 
the enamel ;. beside, when chewed, it debilitates the vessels of 
the gums, turns the teeth yellow, and renders the breath and 
the appearance of the mouth disagreeable. 

232. Healthy persons have generally sound teeth, while 
feeble persons have decayed teeth. For this reason, we should 
try to learn and practise the few simple rules that promote 
health. 



Give an illustration of the removal of sound teeth. 229. How may- 
decaying teeth be preserved ? What should be avoided in the filling of 
teeth ? 230. Whaf practices ghould also be avoided ? 231. What is said 
of acidulated drinks ? What effect has the chewing of tobacco upon the 
teeth ? 232. What is one reason for preserving health ? 



ANATOMY OF THE DIGESTIVE ORGANS. 113 

CHAPTER XIII. 

THE DIGESTIVE ORGANS. 

233. From the earliest existence of the human system to 
the last ray of life, change is impressed upon it by the Giver 
of this curious fabric. New atoms of matter are deposited, 
while the old and now useless particles are constantly 
removed. The material necessary to sustain the growth 
of the body in early life, and also to repair the waste that 
is unceasing to animal existence, is the food we eat. 

234. Food, whether animal or vegetable, has no resem- 
blance to the different tissues of the system. It must undergo 
certain essential alterations before it can become a part of 
the body. The first change is effected by the action of the 
Digestive Organs. 

ANATOMY OF THE DIGESTIVE ORGANS. 

235. The digestive organs are the Mouth, Teeth,* Sal'i- 
va-ry Glands, Phar'ynx, (E-soph'a-gus, (gullet,) Stom'ach, 
In-tes'tines, (bowels,) Lac'te-als, (milk, or chyle vessels,) 
Tho-rac'ic Duct, Liv'er, and the Pan'cre-as, (sweetbread.) 

236. The mouth is an irregular cavity, which contains the 
instruments of mastication and the organs of taste. It is 



* See Chapter XII. 



233. What is impressed upon the human system from its earliest exist- 
ence ? What maintains this change ? 234. Has animal or vegetable food 
any resemblance to the different tissues of which it finally forms a part ? 
By what organs is the first change in the food effected ? 235 — 258. Give 
the anatomy of the digestive organs. 235. Name them. 236. Describe the 
mouth. 

10* 



114 



ANATOMY, PHYSIOLOGY, AND HYGIENE. 



bounded in front by the lips ; on each side by the internal 
surface of the cheeks ; above, by the hard palate (roof of the 
mouth) and teeth of the upper jaw ; below, by the tongue and 
teeth of the lower jaw ; behind, it is continuous with the 
pharynx, but is separated from it by a kind of movable 
curtain, called the soft palate. This may be elevated or 
depressed, so as to close the passage or leave it free. 

237. The salivary glands are six in number; three on 
each side of the jaw. They are called the pa-rot'id, the 
suh-max 'il-la-ry ', and the sub-lin' gual. 

Fig. 58. 




Fig. 58. A view of the salivary glands in their proper situations. 1, The parotid 
gland. 2, Its duct. 3, The submaxillary ~gland. 4, Its duct. 5, The sublingual 
gland, brought to view by the removal of a section of the lower jaw. 

238. The parotid gland, the largest, is situated in front 
of the external ear, and behind the angle of the jaw. A 
duct (Steno's) from this gland opens into the mouth, opposite 
the second molar tooth of the upper jaw. 



237. How many glands about the mouth ? Give their names, 
does fig. 58 represent ? 238. Describe the parotid gland. 



What 



ANATOMY OF THE DIGESTIVE ORGANS. 



115 



239. The submaxillary gland is situated within the lower 
jaw, anterior to its angle. Its excretory duct (Wharton's) 
opens into the mouth by the side of the frce'num lin'guce, 
(bridle of the tongue.) 

240. The sublingual gland is elongated and flattened, 
and situated beneath the mucous membrane of the floor of 
the mouth, on each side of the frsenum linguae. It has seven 
or eight small ducts, which open into the mouth by the side 
of the bridle of the tongue. 

Observation. In the "mumps," the parotid gland is 
diseased. The swelling under the tongue called the "frog" 
is a disease of the sublingual gland. 

Fig. 59. 




Fig. 59. A side view of the face, oesophagus, and trachea. 1, The trachea (wind- 
pipe.) 2, The larynx. 3, The oesophagus. 4,4,4, The muscles of the upper portion 
of the oesophagus, forming the pharynx. 5, The muscle of the cheek. 6, The mus- 
cle that surrounds the mouth. 7, The muscle that forms the floor of the mouth. 

241. The pharynx is a membranous sac, situated upon the 



239. The submaxillary. 240. The sublingual. What observation respect- 
ing these glands ? What does fig. 59 represent ? 



116 ANATOMY, PHYSIOLOGY, AND HYGIENE. 

upper portion of the spinal column. It extends from the base 
of the skull to the top of the tra'che-a, (windpipe,) and is 
continuous with the oesophagus. From the pharynx are four 
passages ; one opens upward and forward to the nose, the 
second leads forward to the mouth, the third downward to the 
trachea and lungs, the fourth downward and backward to the 
stomach. 

242. The oesophagus is a large membranous tube that 
extends behind the trachea, the heart, and lungs, pierces 
the diaphragm, and terminates in the stomach. It is com- 
posed of two membranes — an internal, or mucous, and a 
muscular coat. The latter is composed of two sets of fibres ; 
one extends lengthwise, the other is arranged in circular 
bands. 

243. The stomach is situated in the left side of the abdo- 
men, immediately below and in contact with the diaphragm. 
It has two openings; one connected with the oesophagus, 
called the car'di-ac orifice ; the other connected with the 
upper portion of the small intestine, called the py-lor'ic 
orifice. It is composed of three coats, or membranes. The 
exterior, or serous coat is very tough and strong, and con- 
fines the stomach in its proper situation. The middle, or 
muscular coat is composed of two layers of muscular fibres, 
one set of which is arranged longitudinally, the other circu- 
larly. The interior coat is called the mucous, and is arranged 
in ru'gce, (folds.) The stomach is provided with a multitude 
of small glands, in which is secreted the gastric fluid. 

Illustration. The three coats of the stomach anatomically 
resemble tripe, which is a preparation of the largest stomach of 
the cow or ox. The outer coat is smooth and highly polished. 
The middle coat is composed of minute threads, which are 

241. Describe the pharynx and the passages leading from it. 242. Give 
the structure of the oesophagus. 243. Where is the stomach situated? 
How many coats has it? Describe them. "What article prepared for 
food does the stomach resemble ? 



ANATOMY OF THE DIGESTIVE ORGANS. 117 

arranged in two layers. The fibres of these layers cross each 
other. The inner coat is soft, and presents many folds, usually 
called " the honey-comb." 




Fig. 60. The inner surface of the stomach and duodenum. 1, The lower portion 
of the oesophagus. 2, The openingthrough which the food is passed into the stomach. 
8, The stomach. 9, The opening through which the food passes out of the stomach 
into the duodenum, or upper portion of the small intestine. 10, 11, 14, The duodenum. 
12, 13, Ducts through which the bile and pancreatic fluid pass into it. a, b, c, The 
three coats of the stomach. 

244. The intestines, or alimentary canal, are divided into 
two parts — the small and large. The small intestine is about 
twenty-five feet in length, and is divided into three portions, 
namely, the Du-o-de'nu?n, the Je-ju'num, and the IVe-um. 
The large intestine is about five feet in length, and is divided 
into three parts, namely, the Cce'cum, the Co'lon, and the 
Rec'tum. 

245. The duodenum is somewhat larger than the rest of 
the small intestine, and has received its name from being in 

244. Explain fig. 60. What is the length of the small intestine, and 
how is it divided ? What is the length of the large intestine ? Give its 
divisions. 245. Describe the duodenum. 



118 ANATOMY, PHYSIOLOGY, AND HYGIENE. 

length about the breadth of twelve fingers. It commences at 
the pylorus, and ascends obliquely backward to the under 
surface of the liver. It then descends perpendicularly in 
front of the right kidney, and passes transversely across the 
lower portion of the spinal column, behind the colon, and 
terminates in the jejunum. The ducts from the liver and 
pancreas open into the perpendicular portion, about six inches 
from the stomach. 

246. The jejunum is continuous with the duodenum. It 
is thicker than the rest of the small intestine, and has a 
pinkish tinge. 

247. The ileum is smaller, and thinner in texture, and 
somewhat paler, than the jejunum. There is no mark to dis- 
tinguish the termination of the one or the commencement of 
the other. The ileum terminates near the right haunch-bone, 
by a valvular opening into the colon at an obtuse angle. 
This arrangement prevents the passing of substances from the 
colon into the ileum. The jejunum and ileum are sur- 
rounded above and at the sides by the colon. 

248. The small intestine, like the stomach, has three coats. 
The inner, or mucous coat is thrown into folds, or valves. In 
consequence of this valvular arrangement, the mucous mem- 
brane is more extensive than the other tissues, and gives a 
greater extent of surface with which the aliment comes in 
contact. There are imbedded under this membrane an 
immense number of minute glands, and it has a great number 
of piles, like those upon velvet. For this reason, this mem- 
brane is sometimes called the vil'lous coat. 

249. The ccecum is the blind pouch, or cul-de-sac, at the 
commencement of the large intestine. Attached to its ex- 
tremity is the ap-pend'ix verm-i-form'is, (a long, worm- 

What important ducts open into it ? 246. Describe the jejunum. 
247. The ileum. 248. What is said of the coats of the intestines ? Why 
is the mucous membrane sometimes called the villous coat ? 249. Describe 
the c cecum. 



ANATOMY OF THE DIGESTIVE ORGANS. 



119 



shaped tube.) It is from one to six inches in length, and of 
the size of a goose-quill. 

250. The colon is divided into three parts — the ascending, 
transverse, and descending. The ascending colon passes 
upward from the right haunch-bone to the under surface of 
the liver. It then bends inward, and crosses the upper part 
of the abdomen, below the liver and stomach, to the left side, 
under the name of the transverse colon. At the left side, it 
turns, and descends to the left haunch-bone, and is called the 
descending colon. Here it makes a peculiar curve upon itself, 
which is called the sigmoid flex' ure. 

Fig. 61. 




Fig. 61. 1, 1, The duodenum. 2, 2, The small intestine. 3, The junction of the 
small intestine with the colon. 4, The appendix vermiform is. 5, Theccecum. 6, The 
ascending colon. 7, The transverse colon. 8, The descending colon. 9, The sig- 
moid flexure of the colon. 10, The rectum. 



250. Describe the course of the divisions of the colon. Explain, fig. 61. 



120 ANATOMY, PHYSIOLOGY, AND HYGIENE. 

251. The rectum is the termination of the large intestine. 
The large intestine has three coats, like the stomach and 
small intestine. The longitudinal fibres of the muscular coat 
are collected into three bands. These bands are nearly one 
half shorter than the intestine, and give it a sacculated 
appearance, which is characteristic of the coecum and colon. 

252. The lacteals are minute vessels, which commence 
in the villi, upon the mucous surface of the small intestine. 
From the intestine they pass between the membranes of the 
mes'en-ter-y to small glands, which they enter. The first 
range of glands collects many small vessels, and transmits a 
few larger branches to a second range of glands ; and, final- 
ly, after passing through several successive ranges of these 
glandular bodies, the lacteals, diminished in number and in- 
creased in size, proceed to the enlarged portion of the thoracic 
duct, into which they open. They are most numerous in the 
upper portion of the small intestine. 

253. The thoracic duct commences in the abdomen, by 
a considerable dilatation, which is situated in front of the lower 
portion of the spinal column. From this point, it passes 
through the diaphragm, and ascends to the lower part of the 
neck. In its ascent, it lies anterior to the spine, and by the 
side of the aorta and oesophagus. At the lower part of the 
neck, it makes a sudden turn downward and forward, and 
terminates by opening into a large vein which passes to the 
heart. The thoracic duct is equal in diameter to a goose- 
quill, and, at its termination, is provided with a pair of semi- 
lunar valves, which prevent the admission of venous blood 
into its cylinder. 

251. What is said of the arrangement of the fibres of the muscular coat 
of the large intestine ? 252. "What are the lacteals ? Give their course 
from the mucous coat of the intestine to the thoracic duct. 253. Describe 
the course of the thoracic duct. How is the venous blood prevented from 
passing into this duct ? 



ANATOMY OF THE DIGESTIVE ORGANS. 121 

Fig. 62. 




Fig. 62. A portion of the small intestine, lacteal vessels, mesenteric glands, and 
thoracic duct. 1, The intestine. 2, 3, 4, Mesenteric glands, through which the 
lacteals pass to the thoracic duct. 5, 6, The thoracic duct. 7, The point in the neck 
where it turns down to enter the vein at 8. 9, 10, The aorta. 11, 12, "Vessels of the 
neck. 13, 14, 15, The large veins that convey the blood and chyle to the heart. 
17, 17, The spinal column. 18, The diaphragm, (midriff.) 

Observation. The mesenteric glands, which are situated 
between two layers of serous membrane (mesentery) that 
connects the small intestine with the spinal column, occasion- 
ally become diseased in childhood, and prevent the chyle 

Explain fig. 62. What is said respecting the mesenteric glands ? 
11 



122 ANATOMY, PHYSIOLOGY, AND HYGIENE. 

from passing to the thoracic duct. Children thus affected have 
a voracious appetite, and at the same time are becoming more 
and more emaciated. The disease is called mesenteric con- 
sumption. 

254. The liver, a gland appended to the alimentary canal, 
is the largest organ in the system, and weighs about four 
pounds. It is situated in the right side, below the diaphragm, 
and is composed of several lobes. Its upper surface is con- 
vex ; its under, concave. This organ is retained in its place 
by several ligaments. It performs the double office of sepa- 
rating impurities from the venous blood, and of secreting a 
fluid (bile) necessary to chyliiication. On the under surface 
of the liver is a membranous sac, called the gall-cyst, which 
is generally considered as a reservoir for the bile. 

Fig. 63. 




Fig. 63. The under surface of the liver. 1, The right lobe. 2, The left. 3, 4, 
Smaller lobes. 10, The gall-bladder, or cyst, lodged in its depression. 17, The notch 
on the posterior border, for the spinal column. 

Observation. A good idea of the liver and intestines can 
be obtained by examining these parts of a pig. In this animal, 
the sacs, or pouches, of the large intestine are well denned. 

255. The pancreas is a long, flattened gland, analogous to 

254. Describe the liver. 255. What is said of the pancreas ? 



ANATOMY OF THE DIGESTIVE ORGANS. 123 

the salivary glands. It is about six inches in length, weighs 
three or four ounces, and is situated transversely across the 
posterior wall of the abdomen, behind the stomach. A duct 
from this organ opens into the duodenum. 

256. The spleen, (milt,) so called because the ancients 
supposed it to be the seat of melancholy, is an oblong, flat- 
tened organ, situated in the left side, in contact with the dia- 
phragm, stomach, and the pancreas. It is of a dark, bluish 
color, and is abundantly supplied with blood, but has no duct 
which serves as an outlet for any secretion. Its use is not 
well determined. 

Fisc. 64. 




Fig. 64. The pancreas with its duct, through which the pancreatic secretion passes 
into the duodenum. 

257. The omentum (caul) consists of four layers of the 
serous membrane, which descends from the stomach and 
transverse colon. A quantity of adipose matter is deposited 
around its vessels, which ramify through its structure. Its 
function is twofold in the animal economy. 1st. It protects 
the intestines from cold. 2d. It facilitates the movements 
of the intestines upon each other during their vermicular, or 
worm-like action. 

258. Every part of the digestive apparatus is supplied with 
arteries, veins, lymphatics, and nervous filaments, from the 
ganglionic system of nerves. 

256. Why is the spleen so called ? "What is peculiar to this organ ? 
257- Of what is the omentum composed ? What is its use ? 258. With 
what is every part of the digestive apparatus supplied ? 



124 ANATOMY, PHYSIOLOGY, AND HYGIENE. 

CHAPTER XIV. 

PHYSIOLOGY OF THE DIGESTIVE ORGANS. 

259. Substances received into the stomach as food, must 
necessarily undergo many changes before they are fitted to 
form part of the animal body. The solid portions are re- 
duced to a fluid state, and those parts that will nourish the 
body are separated from the waste material. 

260. The first preparation of food for admission into the 
system, consists in its proper mastication. The lips in front, 
the cheeks upon the side, the soft palate, by closing down 
upon the base of the tongue, retain the food in the mouth, 
while it is subjected to the process of mas-ti-ca'tion, (chew- 
ing.) The tongue rolls the mass around, and keeps it between 
the teeth, while they divide the food to a fineness suitable for 
the stomach. 

261. While the food is in process of mastication, there is 
incorporated with it a considerable amount of sa-li'va, (spittle.) 
This fluid is furnished by the salivary glands, situated in the 
vicinity of the mouth. The saliva moistens and softens the 
food, so that, when carried into the pharynx, it is passed, with 
ease, through the oesophagus into the stomach. 

262. When the food has been properly masticated, (and in 
rapid eaters when it is not,) the soft palate is raised from the 
base of the tongue backward, so as to close the posterior open- 
ing through the nostrils. By a movement of the muscles of 
the tongue, cheeks, and floor of the mouth, simultaneous with 

259 — 272. Give the physiology of the digestive organs. 259. "What is neces- 
sary before food can nourish the body ? 260. Describe how mastication is 
performed. 261. Of what use is the saliva in the process of mastication ? 
262. How is the food pressed into the pharynx ? 



PHYSIOLOGY OF THE DIGESTIVE ORGANS. 125 

that of the soft palate, the food is pressed into the upper part 
of the pharynx. 

263. When in the pharynx, the food and drink are pre- 
vented from passing into the trachea by a simple valve-like 
arrangement, called the ep-i-glot'tis. The ordinary position 
of this little organ is perpendicular, so as not to obstruct the 
passage of air into the lungs ; but in the act of swallowing, 
it is brought directly over the opening of the trachea, called 
the glot'tis. The food, being forced backward, passes rapidly 
over the epiglottis into the oesophagus, where the circular band 
of muscular fibres above, contracts and forces the food to the 
next lower band. Each band relaxes and contracts succes- 
sively, and thus presses the alimentary ball downward and 
onward to the stomach.* 

Observation. If air is inhaled when the food or drink is 
passing over the glottis, some portions of it may be carried 
into the larynx or trachea. This produces violent spasmodic 
coughing, and most generally occurs when an attempt is made 
to speak while masticating food ; therefore, never talk when 
the mouth contains food. 

264. When the food reaches the stomach, the gastric glands 
are excited to action, and they secrete a powerful solvent, 
called gastric juice. The presence of food in the stomach also 
increases a contractile action of the muscular coat, by which 
the position of the food is changed from one part of this cavity 
to another. Thus the aliment is brought in contact with the 
mucous membrane, and each portion of it becomes saturated 
with gastric juice, by which it is softened, or dissolved into 



* The process of deglutition may be comprehended by analyzing 
the operation of swallowing food or saliva. 



263. "Whfen the food is in the pharynx, how is it prevented from passing 
into the trachea, or windpipe ? Describe how it is passed into the stom- 
ach ? Give the observation. 264. Describe how the food in the stomach 
is converted into chyme. 

11 * 



126 ANATOMY, PHYSIOLOGY, AND HYGIENE. 

a pulpy homogeneous mass, of a creamy consistence, called 
Chyme. The food is not all converted into chyme at the same 
time $ but as fast as it is changed, it passes through the pyloric 
orifice into the duodenum. 

Observation. The gastric juice has the property of coagu- 
lating liquid albuminous matter when mixed with it. It is 
this property of rennet, which is an infusion of the fourth 
stomach of the calf, by which milk is coagulated, or formed 
into " curd." 

265. The chyme is conveyed through the pyloric orifice of 
the stomach into the duodenum. The chyme not only excites 
an action in the duodenum, but also in the liver and pancreas. 
Mucus is then secreted by the duodenum, Hie by the liver, 
and pancreatic fluid by the pancreas. The bile and pancre- 
atic fluid are conveyed into the duodenum, and mixed with 
the chyme. By the action of these different fluids, the chyme 
is converted into a fluid of a whitish color, called Chyle, and 
into residuum. 

Observation. The bile has no agency in the change 
through which the food passes in the stomach. In a healthy 
condition of this organ, no bile is found in it. The common 
belief, that the stomach has a redundancy of this secretion, is 
erroneous. If bile is ejected in vomiting, it merely shows, 
not only that the action of the stomach is inverted, but also 
that of the duodenum. A powerful emetic will, in this way, 
generally bring this fluid from the most healthy stomach. A 
knowledge of this fact might save many a stomach from the 
evils of emetics, administered on false impressions of their 
necessity, and continued from the corroboration of these by 
the appearance of bile, till derangement, and perhaps perma- 
nent disease, are the consequences. 

266. The chyle and residual matter are moved over the 

"What peculiar property has gastric juice ? 265. Where and how is 
chyme converted into chyle ? What is said in regard to the bile ? 266. What 
becomes of the chyle ? 



PHYSIOLOGY OF THE DIGESTIVE ORGANS. 127 

mucous surface of the small intestine, by the action of its 
muscular coat. As the chyle is carried along the tract of the 
intestine, it comes in contact with the villi, where the lacteal 
vessels commence. These imbibe, or take up, the chyle, and 
transfer it through the mesenteric glands into the thoracic duct, 
through which it is conveyed into a large vein at the lower 
part of the neck. In this vein the chyle is mixed with the 
venous fluid. The residual matter is conveyed into the large 
intestine, through which it is carried and excreted from the 
system. 

267. In the process of digestion, the food is subjected to 
five different changes. 1st. The chewing and admixture of 
the saliva with the food ; this process is called mastication. 

268. 2d. The change through which the food passes in 
the stomach by its muscular contraction, and the secretion 
from the gastric glands ; this is called chymijication. 

269. 3d. The conversion of the homogeneous chyme, by 
the agency of the bile and pancreatic secretions, into a fluid 
of milk-like appearance ; this is chylijication. 

270. 4th. The absorption of the chyle by the lac teals, 
and its transfer through them and the thoracic duct, into the 
subclavian vein at the lower part of the neck.* 

271. 5th. The separation and excretion of the residuum. 

272. Perfection of the second process of digestion requires 
thorough and slow mastication. The formation of proper 
chyle demands appropriate mastication and chymification ; 
while a healthy action of the lacteals requires that all the 
anterior stages of the digestive process be as perfect as 
possible. 

* The chyle is changed by the lacteals and mesenteric glands, but 
the nature of this change is not, as yet, well denned or understood. 

Of the residuum ? 267. Recapitulate the five changes in the digestive 
process. 

Note. Let the pupil review the anatomy and physiology of the digestive organs, 
from figs. 62 and 65, or from anatomical outline plate No. 5. 



128 ANATOMY, PHYSIOLOGY, AND HYGIENE. 

Fig. 65. 




Fig. 65. An ideal view of the organs of digestion, opened nearly the whole length. 
I, The upper jaw. 2, The lower jaw. 3, The tongue. 4, The roof of the mouth. 
5, The oesophagus. 6, The trachea. 7, The parotid gland. 8, The sublingual gland. 
9, The stomach. 10, 10, The liver. 11, The gall-cyst. 12, The duct that conveys 
the bile to the duodenum, (13, 13.) 14, The pancreas. 15, 15, 15, 15, The small in- 
testine. 16, The opening of the small intestine into the large intestine. 17,18,19,20, 
The large, intestine. 21, The spleen. 22, The upper part of the spinal column. 



HYGIENE OF THE DIGESTIVE ORGANS. 129 

CHAPTER XV. 

HYGIENE OF THE DIGESTIVE ORGANS. 

273. It is a law of the system, that each organ is excited 
to healthy and efficient action, when influenced by its appro- 
priate stimulus. Accordingly, nutrient food, that is adapted 
to the wants of the system, imparts a healthy stimulation to 
the salivary glands during the process of mastication. The 
food that is well masticated, and has blended with it a proper 
amount of saliva, will induce a healthy action in the stomach. 
Well-prepared chyme is the natural stimulus of the duodenum, 
liver, and pancreas ; pure chyle is the appropriate excitant of 
the lacteal vessels. 

274. The perfection of the digestive process, as well as 
the health of the general system, requires the observance of 
certain conditions. These will be considered under four 
heads : — 1st. The Quantity of food that should be taken. 
2d. Its Quality. 3d. The Manner in which it should be 
taken. 4th. The Condition of the system when food is 
taken. 

275. The quantity of food necessary for the system, 
varies. Age, occupation, temperament, temperature, habits, 
amount of clothing, health and disease are among the circum- 
stances which produce the variation. 

276. The child and youth require food to promote the 

273 — 330. Give the hygiene of the digestive organs. 273. Give a law 
of the system. "What is the appropriate stimulus of the salivary glands 
during mastication ? Of the stomach ? Of the duodenum ? Of the 
lacteal vessels ? 274. "What does the perfection of the digestive organs 
require ? 275. What exert an influence on the quantity of food necessary 
for the system ? 



130 ANATOMY, PHYSIOLOGY, AND HYGIENE. 

growth of the different parts of the body. The more rapid 
the growth of the child, the greater the demand for food. 
This accounts for the keen appetite and vigorous digestion in 
childhood. When the youth has attained his full growth, this 
necessity for nutriment ceases ; after this period of life, if the 
same amount of food is taken, and there is no increase of 
labor or exertion, the digestive apparatus will become diseased, 
and the vigor of the whole system diminished. 

Observation. When the body has become emaciated from 
want of nutriment, either from famine or disease, there is an 
increased demand for food. This may be gratified with 
impunity until the individual has regained the usual size, but 
repletion should be avoided. 

277. Food is required to repair the waste, or loss of sub- 
stance that attends action. In every department of nature, 
waste, or loss of substance, attends and follows action. When 
an individual increases his exercise, — changes from light to se- 
vere labor, — or the inactive and sedentary undertake journeys 
for pleasure, the fluids of the system circulate with increased 
energy. The old and exhausted particles of matter are more 
rapidly removed through the action of the vessels of the skin, 
lungs, kidneys, and other organs, and their places are filled 
with new atoms, deposited by the small blood-vessels. 

278. As the chyle supplies the blood with the newly vital- 
ized particles of matter, there is, consequently, an increased 
demand for food. This want of the system induces, in 
general, a sensation of hunger or appetite, which may be 
regarded as an indication of the general state of the body. 
The sympathy that exists throughout the system accords to 

276. At what age is the appetite keen and the digestion vigorous ? Why ? 
"What is said in regard to the quantity of food when the youth has attained 
his growth ? What exception, as given in the observation ? 277- Give 
another demand for food. What effect has increased exercise upon the 
system ? 278. How are the new particles of matter supplied ? What does 
this induce ? 



HYGIENE OF THE DIGESTIVE ORGANS. 131 

the stomach the power of making known this state to the 
nervous system, and, if the functions of this faithful monitor 
have not been impaired by disease, abuse, or habit, the call is 
imperious, and should be regarded. 

279. When exercise or labor is lessened, the quantity of 
food should be diminished. When a person who has been 
accustomed to active exercise, or even hard manual labor, 
suddenly changes to an employment that demands less activity, 
the waste attendant on action will be diminished in a cor- 
responding degree ; hence the quantity of food should be 
lessened in nearly the same proportion as the amount of 
exercise is diminished. If this principle be disregarded, the 
tone of the digestive organs will be impaired, and the health 
of the system enfeebled. 

280. This remark is applicable to those students who have 
left laborious employments to attend school. Although the 
health is firm, and the appetite keen from habit, yet every 
pupil should practise some self-denial, and not eat as much as 
the appetite craves, the first week of the session. After some 
days, the real wants of the system will generally be manifested 
by a corresponding sensation of hunger. 

Observation. It is a common observation that in academies 
and colleges, the older students from the country, who have 
been accustomed to hard manual labor, suffer more frequently 
from defective digestion and impaired health than the younger 
and feebler students from the larger towns and cities. 

281. Food is essential in maintaining a proper temper- 
ature of the system. The heat of the system, at least in part, 
is produced in the minute vessels of the several organs, by the 
union of oxygen with carbon and hydrogen, which the food 
and drink contain. The amount of heat generated, is great- 

279. "Why should the quantity of food be diminished when the exercise 
is lessened ? "What effect if this principle be disregarded ? 280. To what 
class is this remark applicable ? What is often observed among students 
in academies and colleges ? 281. State another demand for food. What is 
one source of heat in the body ? 



132 ANATOMY, PHYSIOLOGY, AND HYGIENE. 

est when it is most rapidly removed from the system, which 
occurs in cold weather. This is the cause of the system 
requiring more food in winter than summer. 

Observation. Persons that do not have food sufficient for 
the natural wants of the system, require more clothing than- 
\hose who are well fed. 

282. The last-mentioned principle plainly indicates the 
propriety and necessity of lessening the quantity of food as 
the warm season approaches. Were this practised, the tone 
of the stomach and the vigor of the system would continue 
unimpaired, the " season complaints " would be avoided, and 
the u strengthening bitters " would not be sought to create 
an appetite. 

Observation. Stable-keepers and herdsmen are aware of 
the fact, that as the warm season commences, then animals 
require less food. Instinct teaches these animals more truly, 
in this particular, than man allows reason to guide him. 

283. The quantity of food should have reference to the 
present condition of the digestive organs. If they are weak- 
ened or diseased, so that but a small quantity of food can be 
properly digested or changed, that amount only should be 
taken. Food does not invigorate the system, except it is 
changed, as has been described in previous paragraphs. 

Observation. When taking care of a sick child, the anxiety 
of the mother and the sufferings of the child may induce her 
to give food when it would be highly injurious. The attend- 
ing physician is the only proper person to direct what quantity 
should be given. 

284. The quantity of food is modified, in some degree, by 

Why do we eat more in the winter than in the summer ? What practi- 
cal observation is given ? 282. Why should the quantity of food be 
lessened as warm weather commences ? What would be avoided if this 
principle were obeyed? 283. Why should the present condition of the 
digestive organs be regarded in reference to the quantity of food ? Mention 
an instance in which it would be injudicious to give food. 



HYGIENE OF THE DIGESTIVE ORGANS. 133 

f 

habit. A healthy person, whose exercise is in pure air, may 
be accustomed to take more food than is necessary. The 
useless excess is removed from the system by the waste out- 
lets, as the skin, lungs, liver, kidneys, &c. In such cases, 
if food is not taken in the usual quantity, there will be a feel- 
ing of emptiness, if not of hunger, from the want of the usual 
distention of the stomach. This condition of the digestive 
organs may be the result of disease, but it is more frequently 
produced by inordinate daily indulgence in eating, amounting 
almost to gluttony. 

285. Large quantities of food oppress the stomach, and 
cause general languor of the whole body. This is produced 
by the extra demands made on the system for an increased 
supply of blood and nervous fluid to enable the stomach to 
free itself of its burden. Thus, when we intend to make any 
extraordinary effort, mental or physical, at least for one meal, 
we should eat less food than usual, rather than a greater 
quantity. 

286. No more food should be eaten than is barely suf 
ficient to satisfy the appetite. Nor should appetite be con- 
founded with taste. The one is a natural desire for food to 
supply the wants of the system ; the other is an artificial 
desire merely to gratify the palate. 

287. Although many things may aid us in determining the 
quantity of food proper for an individual, yet there is no 
certain guide in all cases. It is maintained by some, that the 
sensation of hunger or appetite is always an indication of the 
want of food, while the absence of this peculiar sensation is 
regarded as conclusive evidence that aliment is not demanded. 



284. Show the effect of habit upon the quantity of food that is eaten. 
"What is said in regard to inordinate eating ? 285. What is the effect of 
eating large quantities of food ? "What suggestion when an extraordinary 
effort, either mental or physical, is to be made ? 286. How much food 
should generally be eaten ? 287. What is the assertion of some persons 
relative to the quantity of food necessary for the system ? 
12 



134 ANATOMY, PHYSIOLOGY, AND HYGIENE. 



% 



This assertion is not correct, as an appetite may be created 
for food by condiments and gormandizing, which is as arti- 
ficial and as morbid as that which craves tobacco or ardent 
spirits. On the other hand, a structural or functional disease 
of the brain may prevent that organ from taking cognizance 
of the sensations of the stomach, when the system actually 
requires nourishment. Observation shows, that disease, habit, 
the state of the mind, and other circumstances, exert an 
influence on the appetite. 

Observation. Dr. Beaumont noticed, in the experiments 
upon Alexis St. Martin, that after a certain amount of food 
was converted into chyme, the gastric juice ceased to ooze 
from the coats of the stomach. Consequently, it has been 
inferred by some writers on physiology, that the glands which 
supply the gastric fluid, by a species of instinctive intelligence, 
would only secrete enough fluid to convert into chyme the 
aliment needed to supply the real wants of the system. What 
are the reasons for this inference ? There is no evidence that 
the gastric glands possess instinctive intelligence, and can 
there be a reason adduced, why they may not be stimulated 
to extra functional action as well as other organs, and why 
they may not also be influenced by habit ? 

288. While all agree that the remote or predisposing 
cause of hunger is, usually, a demand of the system for 
nutrient material, the proximate or immediate cause of the 
sensation of hunger is not clearly understood. Some phys- 
iologists suppose that it is produced by an engorged condition 
of the glands of the stomach which supply the gastric juice ; 
while others maintain that it depends on a peculiar condi- 
tion of the nervous system. 

289. The quality of the food best adapted to the wants of 
the system is modified by many circumstances. There are 

What does observation show? 288. "What is said of the causes of 
hunger? 289. Why is not the same kind of food adapted to different 
individuals ? 



HYGIENE OF THE DIGESTIVE ORGANS. 135 

many varieties of food, and these are much modified by the 
different methods of preparation. The same kind of food is 
not equally well adapted to different individuals, or to the 
same individual in all conditions ; as vocation, health, exposure, 
habits of life, season, climate, &c, influence the condition of 
the system. 

290. The question is not well settled, whether animal or 
vegetable food is best adapted to nourish man. There are 
nations, particularly in the torrid zone, that subsist, exclusively, 
on vegetables ; while those of the frigid zone feed on fish or 
animal food. In the temperate zone, among civilized nations, 
a mixed diet is almost universal. When we consider the 
organization of the human system, the form and arrangement 
of the teeth, the structure of the stomach and intestines, we 
are led to conclude, that both animal and vegetable food is 
requisite, and that a mixed diet is most conducive to strength, 
health, and long life. 

291. The food should be adapted to the distensible charac- 
ter of the stomach and alimentary canal. The former will be 
full, if it contain only a gill ; it may be so distended as to 
contain a quart. The same is true of the intestines. If the 
food is concentrated, or contains the quantity of nutriment 
which the system requires, in small bulk, the stomach and 
intestines will need the stimulation of distention and friction, 
which is consequent upon the introduction and transit of the 
innutritious material into and through the alimentary canal. 
If the food is deficient in innutritious matter, the tendency 
is, to produce an inactive and diseased condition of the diges- 
tive organs. For this reason, nutrient food should have blend- 
ed with it innutritious material. Unbolted wheat bread is 
more healthy than hot flour cakes ; ripe fruits and vegetables 
than rich pies, or jellies. 

290. "What is said of the adaptation of animal and vegetable food to man. 
291. What is said of the distensible character of the stomach and 
alimentary canal ? What is the effect of eating highly concentrated 
food ? Why is the unbolten wheat bread more healthy than flour cakes ? 



136 ANATOMY, PHYSIOLOGY, AND HYGIENE. 

292. The observance of this rule is of more importance to 
students, sedentary mechanics, and those individuals whose 
digestive apparatus has been enfeebled, than to those of active 
habits and firm health. This principle has been and may- 
be illustrated by experiments upon the inferior animals. 
Feed a dog with pure sugar or olive-oil, (articles that contain 
no innutritious matter,) for several weeks, and the evil effects 
of concentrated nutriment will be manifested. At first, the 
dog will take his food with avidity, and seem to thrive upon it ; 
soon this desire for food will diminish, his body emaciate, his 
eye become ulcerated, and in a few weeks he will die ; but 
mix bran or sawdust with the sugar or oil, and the health and 
vigor of the animal will be maintained for months. A similar 
phenomenon will be manifested, if grain only be given to a 
horse, without hay, straw, or material of like character. 

Observation. The circumstance that different articles of 
food contain different proportions of waste, or innutritious mat- 
ter, may be made practically subservient in the following way : 
If, at any particular season of the year, there is a tendency 
to a diarrhoea, an article that contains a small proportion of 
waste should be selected for food ; but, if there is a tendency 
to an inactive, or costive condition of the intestinal canal, such 
kinds of food should be used as contain the greatest propor- 
tion of waste, as such articles are most stimulating to the 
digestive organs, and, consequently, most laxative. 

293. In the selection of food, the influence of season and 
climate should be considered. Food of a highly stimulating 
character may be used almost with impunity during the cold 
weather of a cold climate ; but in the warm season, and in a 
warm climate, it would be very deleterious. Animal food, 
being more stimulating than vegetable, can be eaten in the 

292. "What classes in the community should observe the last-mentioned 
principle ? How has the effect of concentrated nutriment been illustrated ? 
Show how a proper selection of food may promote the health. 293. What 
kind of food is adapted to cold weather ? To warm weather ? 



HYGIENE OF THE DIGESTIVE ORGANS. 137 

winter ; but vegetable food should be used more freely in the 
spring and summer. 

294. The influence of food on the system is modified by 
the age of the individual. The organs of a child are more 
sensitive and excitable than those of a person advanced in 
years. Therefore a vegetable diet would be most appropriate 
for a child, while stimulating animal food might be conducive 
to the health of a person advanced in life. 

Observation. When the digestive organs are highly 
impressible or diseased, it is very important to adopt a 
nutritious, unstimulating, vegetable diet, as soon as the warm 
season commences. 

295. Habit is another strong modifying influence. If a 
person has been accustomed to an animal or vegetable diet, 
and there is a sudden change from one to the other, a diseased 
condition of the system, particularly of the digestive apparatus, 
usually follows. When it is necessary to change our manner 
of living, it should be done gradually.* 

296. Some temperaments require more stimulating food 
than others. As a general rule, those persons whose sensa- 
tions are comparatively obtuse, and movements slow, will be 
benefited by animal food ; while those individuals whose 
constitutions are highly impressible, and whose movements 
are quick and hurried, require a nutritious and unstimulat- 
ing vegetable diet. 



* The system is gradually developed, and all changes of food, 
apparel, labor, exercise, or position, should be gradual. Even a change 
from a bad to a good habit, on this principle, should be gradual. 

294. What kinds of food are appropriate to old age ? "Why ? What 
kinds to childhood ? Why : 295. What is the effect when there is a 
sudden change from a vegetable to an animal diet? How should all 
changes of the system he made ? 296. Do different temperaments require 
different kinds of food ? What general rule is given ? 
12* 



138 



ANATOMY, PHYSIOLOGY, AND HYGIENE. 



TABLE, 

SHOWING THE MEAN TIME OF DIGESTION OF THE DIFFERENT 
ARTICLES OF DIET. 



Articles. 



Apples, sour, hard, . 

, mellow 

, sweet, do., 

Bass, striped, fresh, 

Beans, pod, 

Beef, fresh, lean, rare 
, dry 

steak, 

, with salt only, 

, with mustard, 

, fresh, lean, . . 

, old, hard, salted 

Beets, 

Bread, Avheat, fresh, 

, corn, 

Butter, 

Cabbage head, .... 
, with -vinegar. 

Cake, sponge, .... 
Carrot, orange, . . . 

Catfish, 

Cheese, old, strong, 
Chicken, full-grown, 
Codfish, cured, dry, . 
Corn, green, & beans 

bread, 

cake, 

Custard, 

Dumpling, apple, . . 
Ducks, domesticated 
, wild, 

5, fresh, . . . . < 



Flounder, fresh, . , 
Fowl, domestic, . , 

Goose, 

Lamb, fresh, . . . . 
Liver, beef's, fresh 



Prepara- 
tion. 


Time 




h. m. 


Raw, 


2 50 


Raw, 


2 


Raw, 


1 30 


Broiled, 


3 


Boiled, 


2 30 


Roasted, 


3 


Roasted, 


3 30 


Broiled, 


3 


Boiled, 


3 36 


Boiled, 


3 10 


Fried, 


4 


Boiled, 


4 15 


Boiled, 


3 45 


Baked, 


3 30 


Baked, 


3 15 


Melted, 


3 30 


Raw, 


2 30 


Raw, 


2 


Boiled, 


4 30 


Baked, 


2 30 


Boiled, 


3 15 


Fried, 


3 30 


Raw, 


3 30 


Fricas'd, 


2 45 


Boiled, 


2 


Boiled, 


3 45 


Baked, 


3 15 


Baked, 


3 


Baked, 


2 45 


Boiled, 


3 


Roasted, 


4 


Roasted, 


4 30 


Boiled 
hard, 


3 30 


Boiled 


3 


soft, 


Fried, 


3 30 


Raw, 


2 


Fried, 


3 30 


Boiled, 


4 


Roasted, 


4 


Roasted, 


2 30 


Broiled, 


2 30 


Broiled, 


2 



Meat hashed with 

vegetables. . 
Milk '. 



Mutton, fresh, 



Oysters, fresh, 



Parsnips, . . . 
Pig, sucking. . 
Pigs' feet, soused, 
Pork, fat and lean, 
, recently salted 



steak, 

Potatoes, Irish, . . 

Rice, 

Sago, 

Salmon, salted, . . . 
Sausage, fresh, . . . 
Soup, beef, vegeta- ) 
bles, and bread, ) 

, chicken, . . . 

, mutton, .... 

, oyster, 

Suet, beef, fresh, . . 

, mutton, .... 

Tapioca, 

Tripe, soused, . . . 
Trout, salmon, fresh 

Turkey, domesti- ^ 
cated, .... 



, wild, 

Turnips, fiat, . 
Veal, fresh, . . 



Venison steak, 



Prepara- 
tion. 



Warm'd, 

Boiled, 

Raw, 

Roasted. 

Broiled, 

Boiled, 

Raw, 

Roasted, 

Stewed, 

Boiled, 

Roasted. 

Boiled, 

Roasted. 

Boiled, ' 

Fried, 

Broiled, 

Raw, 

Broiled, 

Boiled, 

Baked, 

Boiled, 

Boiled, 

Boiled, 

Broiled, 

Boiled, 

Boiled, 
Boiled, 
Boiled, 
Boiled, 
Boiled, 
Boiled, 
Boiled, 
Boiled, 
Fried, 

Roasted, 

Boiled, 

Roasted, 

Boiled, 

Broiled, 

Fried, 

Broiled, 



HYGIENE OF THE DIGESTIVE ORGANS. 139 

297. The preceding table exhibits the general results of 
experiments made on Alexis St. Martin, by Dr. Beaumont, 
when he endeavored to ascertain the time required for the 
digestion of different articles of food.* The stomach of St. 
Martin was ruptured by the bursting of a gun. When he 
recovered from the effects of the accident under the surgical 
care of Dr. Beaumont, the stomach became adherent to the 
side, with an external aperture. Nature had formed a kind 
of valve, which closed the aperture from the interior, and thus 
prevented the contents of the stomach from escaping ; but on 
pushing it aside, the process of digestion could be seen. 
Through this opening, the appearance of the coats of the 
stomach and food, at different stages of digestion, were 
examined. 

298. In view of this table, the question may be suggested, 
Is that article of food most appropriate to the system which is 
most easily and speedily digested ? To this it may be replied, 
that the stomach is subject to the same law as the muscles 
and other organs ; exercise, within certain limits, strengthens 
it. If, therefore, we always eat those articles most easily 
digested, the digestive powers will be weakened ; if over- 
worked, they will be exhausted. Hence the kind and amount 
of food should be adapted to the maintenance of the digestive 
powers, and to their gradual invigoration when debilitated. 

Observation. Food that is most easily digested is not al- 
ways most appropriate to a person convalescing from disease. 
If the substance passes rapidly through the digestive pro- 



* The time required for the digestion of the different articles of 
food might vary in other persons ; and would probably vary in the 
same individual at different periods, as the employment, health, 
season, &c, exert a modifying influence. 

297. How was the time required for digesting different articles of food 
ascertained ? 298. How is the question answered, whether that article is 
most appropriate to the system which is most easily digested ? Give 
observation. 



140 ANATOMY, PHYSIOLOGY, AND HYGIENE. 

cess, it may induce a recurrence of the disease. Thus the sim- 
ple preparations which are not stimulating, as water-gruel, are 
better for a sick person than the more digestible beef and fish. 

299. All articles of food may be considered in two rela- 
tions : 1st, As nutritive. 2d, As digestible. Substances are 
nutritious in proportion to their capacity to yield the elements 
of chyle, of which carbon, hydrogen, and nitrogen, are the 
most essential ; they are digestible in proportion to the facility 
with which they are acted upon by the gastric juice. These 
properties should not be confounded in the various articles 
used for food. 

300. Some articles of food contain the elements of chyle in 
great abundance, yet afford but little nutriment, because they 
are difficult of digestion ; while other articles contain but a 
small quantity of these elements, and afford more nourishment, 
because they are more easily affected by the digestive process. 

301. Asa " living body has no power of forming elements, 
or of converting one elementary substance into another, it 
therefore follows that the elements of which the body of an 
animal is composed must be in the food." (Chap. III.) Of 
the essential constituents of the human body, carbon, hydrogen, 
oxygen, azote, or nitrogen, are the most important, because 
they compose the principal part of the animal body ; while 
the other elements are found in very small proportions, and 
many of them only in a few organs of the system. 

Observation. Nitrogen renders food more stimulating, par- 
ticularly if combined with a large quantity of carbon, as beef. 
Those articles that contain the greatest amount of digestible 
carbon are most nutritious, as sugar. Again, food may be 
highly nutritive that contains no carbon or nitrogen, but when 
decomposed afford hydrogen and oxygen, as milk. 

302. The following table, by Pereira, in his treatise on 
Food and Diet, may aid the student in approximating to 
correct conclusions of the quantity of nutriment in different 
kinds of food, and its adaptation to the wants of the system. 



HYGIENE OF THE DIGESTIVE ORGANS. 



141 



TABLE, 

SHOWING THE AVERAGE QUANTITY OF DRY, OR SOLID MATTER, CARBON, 
NITROGEN, AND MOISTURE, IN DIFFERENT ARTICLES OF DIET. 



One hundred Parts. 



Arrowroot, 

Beans, 

Beef, fresh, .... 

Bread, rye, 

Butter, 

Cabbage, , 

Carrot, 

Cherries, 

Chickens, 

Codfish, 

Cucumbers, .... 
Eggs, whites, . . 

, yolk, 

Lard, hog's, .... 
Milk, cow's, .... 

Oats, 

Oatmeal, , 

Olive-oil, 

Oysters, 

Peaches, 

Pears, 

Peas, 

Plums, greengage 

Potatoes, 

Rye, 

Suet, mutton,. . . 
Starch, potato, . . 

, wheat, . . . 

Sugar, maple, . . . 

, refined, . . 

, brown, . . 

Turnips, 

Veal, roasted, . . 
Wheat, 



Dry 

Matter. 


Carbon. 


Nitrogen. 


81.8 


36.4 




85.89 


38.24 




25 


12.957 


3.752 


67.79 


30.674 




100 


65.6 




7.7 




0.28 


12.4 




0.30 


25.15 






22.7 






20 






2.86 






20 






46.23 






100 


79.098 




12.98 






79.2 


40.154 


1.742 


93.4 






100 


77.50 




12.6 






19.76 






16.12 






84 


35.743 




28.90 






24.1 


10.604 


0.3615 


83.4 


38.530 


1.417 


100 


78.996 




82 


36.44 




85.2 


37.5 
42.1 

42.5 
40.88 




7-5 


3.2175 


0.1275 




52.52 


14.70 


85.5 


39.415 


1.966 



Water. 



18.2 
14.11 
75 
32.21 

92.3* 

87.6 

74.85 

77.3 

80 

97.14 

80 

53.77 

87.02 

20.8 

6.6 

87.4 

80.24 

83.88 

16 

71.10 

75.9 

16.6 

18" 
14.8 



92.5 
14.5* 



Note. Let the pupil mention those articles of food that are most nutri- 
tious, from a review of this table, and the last four paragraphs. 



142 ANATOMY, PHYSIOLOGY, AND HYGIENE. 



CHAPTER XYI. 

HYGIENE OF THE DIGESTIVE ORGANS, CONTINUED. 

303. The manner in which food should be taken is of much 
practical importance ; upon it the health of the digestive organs 
measurably depends. But few circumstances modify the 
proper manner of taking food, or should exercise any con- 
trolling influence. 

304. Food should be taken at regular periods. The inter- 
val between meals should be regulated by the character of the 
food, the age, health, exercise, and habits of the individual. 
The digestive process is more energetic and rapid in the 
young, active, and vigorous, than in the aged, indolent, and 
feeble ; consequently, food should be taken more frequently 
by the former than by the latter class. 

305. In some young and vigorous persons, food may be 
digested in one hour ; in other persons, it may require four 
hours or more. The average time, however, to digest an ordi- 
nary meal, will be from two to four hours. In all instances, 
the stomach will require from one to three hours to recruit 
its exhausted powers after the labor of digesting a meal, 
before it will again enter upon the vigorous performance of 
its duties. 

306. Food should not be taken too frequently. If food is 
taken before the stomach has regained its tone and energy by 
repose, the secretion of the gastric juice, and the contraction 

303. Why is it important that we regard the manner of taking our food ? 
304. How should the intervals between meals be regulated ? 305. What is 
the average time required to digest an ordinary meal ? 306. Why should 
not food be taken too frequently? 



HYGIENE OF THE DIGESTIVE OEGANS. 143 

of the muscular fibres, will be imperfect. Again, if food is 
taken before the digestion of the preceding meal has been 
completed, the effects will be still worse, because the food 
partially digested becomes mixed with that last taken. There- 
fore the interval between each meal should be long enough 
for the whole quantity to be digested, and the time of repose 
should be sufficient to recruit the exhausted organs. The 
feebler the person and the more debilitated the stomach, the 
more important to observe the above directions. 

Observation. In the feeding of infants, as well as in 
supplying food to older children, the preceding suggestions 
should always be regarded. The person who has been con- 
fined by an exhausting sickness, should most scrupulously 
regard this rule, if he wishes to regain his strength and flesh 
with rapidity. As the rapidity of the digestive process is less 
in students and individuals who are engaged in sedentary 
employments, than in stirring agriculturists, the former class 
are more liable to take food too frequently than the latter, 
while its observance is of greater importance to the sedentary 
artisan than to the lively lad and active farmer. 

307. Food should be well masticated. All solid aliments 
should be reduced to a state of comparative fineness, by the 
teeth, before it is swallowed ; the gastric fluid of the stomach 
will then blend with it more readily, and act more vigorously 
in reducing it to chyme. The practice of swallowing solid 
food, slightly masticated, or "bolting" it down, tends to 
derange the digestive process and impair the nutrition of the 
system. 

308. Mastication should be moderate, not rapid. In mas- 
ticating food, the salivary glands are excited to action, and 
some time must elapse before they can secrete saliva in suffi- 

What persons would be benefited by observing tbe preceding- re- 
marks ? 307. Why should food be well masticated ? What is the effect 
of "bolting down "food? 308. How should mastication be performed? 
Why? 



144 ANATOMY, PHYSIOLOGY, AND HYGIENE. 

cient quantities to moisten it. If the aliment is not supplied 
with saliva, digestion is retarded ; besides, in rapid eating, 
more food is generally consumed than the system demands, 
or can be easily digested. Laborers, as well as men of leisure, 
should have ample time for taking their meals. Imperfect 
mastication is a prevailing cause of indigestion. 

309. Food should be masticated and swallowed without 
drink. As the salivary glands supply fluid to moisten the dry 
food, the use of tea, coffee, water, or any other fluid, is not 
demanded by nature's laws while taking a meal. One objec- 
tion to " washing down " the food with drink is, the aliment 
is ' moistened, not with the saliva, but with the drink. This 
tends to induce disease, not only in the salivary organs, by 
leaving them in a state of comparative inactivity, but in 
the stomach, by the deficiency of the salivary stimulus. 
Another is, large quantities of fluids, used as drinks, give 
undue distention to the stomach, and lessen the energy of the 
gastric juice by its dilution, thus retarding digestion. Again, 
drinks taken into the stomach must be removed by absorption 
before the digestion of other articles is commenced. 

Observation. Were it customary not to place drinks on the 
table until the solid food is eaten, the evil arising from drink- 
ing too much at meals would be obviated. The horse is never 
known to leave his provender, nor the ox his blade of grass, to 
wash it down ; but many persons, from habit rather than thirst, 
drink largely during meals. 

310. The peculiar sensation in the mouth and fauces, called 
thirst, may not always arise from the demand for fluids to 
increase the serum (water) of the blood, as in the desire for 
drink attendant on free perspiration, for then, pure water or 
some diluent drink is absolutely necessary ; but it may be the 

Why should all persons have ample time for eating ? 309. Why are 
drinks not necessary while masticating food? Give the objections to 
"washing down" food. What observation relative to drink? 310. Does 
the sensation of thirst always arise from a real want of the system ? 



HYGIENE OF THE DIGESTIVE ORGANS. 145 

result of fever, or local disease of the parts connected with 
the throat. In many instances, thirst may be allayed by chew- 
ing some hard substance, as a dry cracker. This excites a 
secretion from the salivary glands, which removes the disa- 
greeable sensation. In thirst, attendant on a heated condition 
of the system, this practice affords relief, and is safe ; while 
the practice of drinking large quantities of cold fluids, is 
unsafe, and should never be indulged. 

311. Food or drink should not he taken when very hot. 
When, food or drink is taken hot, the vessels of the mucous 
membrane of the gums, mouth, and stomach are unduly stim- 
ulated for a short time ; and this is followed by reaction, 
attended by a loss of tone, and debility of these parts. This 
practice is a fruitful cause of spongy gums, decayed teeth, 
sore mouth, and indigestion. 

312. Food or drink should not he taken very cold. If 
a considerable quantity of very cold food or liquid be taken 
immediately into the stomach, the health will be endangered, 
and the tone of the system will be impaired, from the sudden 
abstraction of heat from the coats of the stomach, and 
from surrounding organs, to impart warmth to the cold food 
or drink. This arrests the digestive process, and the food is 
retained in the stomach too long, and causes oppression and 
irritation. Consequently, food and drink that are moderately 
heated are best adapted to the natural condition of the diges- 
tive apparatus. 

Observation. Food of an injurious quality, or taken in an 
improper manner, affects the inferior animals as well as man. 
The teeth of cows that are closely penned in cities, and are 
fed on distillery slops, or the unhealthy slops and remnants 
of kitchens, decay and fall out in about two years. Can the 
milk of such diseased animals be healthy — the proper nour- 
ishment for children ? 

Give instances when it does and when it does not. 311. "Why should not 
food or drink be taken hot? 312. Why should they not be taken cold? 
Show some of the effects of improper food upon the inferior animals. 
13 



146 ANATOMY, PHYSIOLOGY, AND HYGIENE. 

313. The condition of the system should be regarded when 
food is taken. This is necessary, as the present and ulterior 
condition of the digestive apparatus is strongly influenced by 
the state of the other organs of the system. 

314. Food should not be taken immediately after severe 
exertion, either of the body or mind. For all organs in 
action require and receive more blood and nervous fluid, than 
when at rest. This is true of the brain, muscles, and vo- 
cal organs, when they have been actively exercised. The 
increased amount of fluid, both sanguineous and nervous, 
supplied to any organ during extra functional action, is ab- 
stracted from other parts of the system. This enfeebles and 
prostrates the parts that supply the blood and nervous fluid to 
the active organ. Again, when any organ has been in vigor- 
ous action for a few hours, some time will elapse before the 
increased action of the arteries and nerves abates, and a due 
supply of fluids is transmitted to other organs, or an equilibrium 
of action in the system is reestablished. 

315". Thus food should not be taken immediately after 
severe mental labor, protracted speaking, continued singing, 
or laborious manual toil ; as the digestive organs will be in a 
state of comparative debility, and consequently unfit to digest 
food. From thirty to sixty minutes should elapse, after the 
cessation of severe employment, before food is taken. This 
time may be spent in cheerful amusement or social conversa- 
tion. 

Observation. The practice of students and accountants 
going immediately from severe mental labor to their meals, 
is a pernicious one, and a fruitful cause of indigestion and 
mental debility. The custom of farmers and mechanics 



313. Should the condition of the system be regarded in taking food ? 
314. When should food not be taken ? Why ? What is the result when 
an organ has been in vigorous action ? 315. After the cessation of severe 
toil, how much time should expire before eating ? What is one cause of 
indigestion among students and accountants ? 



HYGIENE OF THE DIGESTIVE ORGANS. 147 

hurrying from their toil to the dinner-table, does much to 
cause dyspepsia and debility among these classes in com- 
munity. 

316. Severe mental or manual toil should not he entered 
upon immediately after eating. As there is an increased 
amount of blood and nervous fluid supplied to the stomach 
and alimentary canal during the digestion of food, a deficiency 
exists in other organs. This is evinced by a slight paleness 
of the skin, and a disinclination to active thought and exercise. 
Under such circumstances, if either the mind, vocal organs, 
or muscles are called into energetic action, there will be an 
abstraction of the necessary amount of blood and ner- 
vous fluid from the stomach, and the process of digestion 
will be arrested. This will not only cause disease of the 
digestive organs, but chyle will not be formed, to nourish the 
system. 

Illustration. An English gentleman fed two dogs upon 
similar articles of food. He permitted one to remain quiet in 
a dark room ; the other he sent in pursuit of game. At the 
expiration of one hour, he had both killed. The stomach of 
the dog that had remained quiet was nearly empty. The 
food had been properly changed and carried forward into the 
alimentary canal. In the stomach of the dog that had used 
his muscles in chasing game, the aliment remained nearly 
unaltered. 

317. The same principle may be applied to the action of 
the organs of man. If his mind or muscles act intensely 
soon after eating, the stomach will not be sufficiently stimu- 
lated by blood and nervous fluid to change the food in a 
suitable period. The Spanish practice of having a " siesta," 
or sleep after dinner, is far better than the custom of the 

316. Why should not severe manual or mental exertion he made imme- 
diately after eating ? State the illustration. 317. May this principle he 
applied to the action of the human stomach ? What is said of the Spanish 
custom of resting after dinner ? 



148 ANATOMY, PHYSIOLOGY, AND HYGIENE. 

Anglo-Saxon race, who hurry from their meals to the field, 
shop, or study, in order to save time, which, in too many 
instances, is lost by a sense of oppression and suffering which 
soon follows. 

318. In some instances of good health, the infringement of 
this organic law may seem to pass with impunity, but Nature, 
though lenient, sooner or later asserts her claims. The prac- 
tice of the Spaniard may be improved by indulging, for an 
hour before resuming toil, in moderate exercise of the muscu- 
lar system, conjoined with agreeable conversation and a 
hearty laugh, as this facilitates digestion, and tends to " shake 
the cobwebs from the brain." 

Observation. No judicious teamster drives his animals as 
soon as they have swallowed their food, but gives them a 
period for repose, so that their food may be digested, and 
their systems invigorated. In this way, he secures the greatest 
amount of labor from his team. 

319. The mind exerts an influence upon the digestive pro- 
cess. This is clearly exhibited, when an individual receives 
intelligence of the loss of a friend or of property. He 
may at the time be sitting before a plentiful board, with a 
keen appetite ; but the unexpected news destroys it, because 
the excited brain withholds its stimulus. This shows the pro- 
priety of avoiding absorbing topics of thought at meals, as 
labored discussions and matters of business ; but substitute 
cheerful and light conversation, enlivening wit, humor, the 
social intercourse of family and friends ; these keep the brain 
in action, but not in toil. Under such circumstances, the 
blood and nervous fluid flow freely, the work of digestion is 
readily commenced, and easily carried on. 

320. Indigestion arising from a prostration of the nervous 
system, should be treated with great care. The food should 

Of the Anglo-Saxon race ? 318. How can the Spanish custom be im- 
proved ? 319. How is the influence of the mind on the digestive process 
exhibited ? "What does it show the necessity of avoiding ? 320. How 
should indigestion arising from nervous prostration be treated ? 



HYGIENE OF THE . DIGESTIVE ORGANS. 149 

be simple, nutritious, moderate in quantity, and taken at regu- 
lar periods. Large quantities of stimulating food, frequently 
taken, serve to increase the nervous prostration. Those 
afflicted should exercise in the open air, and engage in social 
conversation, that the brain may be excited to a natural or 
healthy action, in order that it may impart to the digestive 
organs the necessary stimulation. 

321. Perso?is should abstain from eating, at least three 
hours before retiring for sleep. It is no unusual occurrence, 
for those persons who have eaten heartily immediately before 
retiring to sleep, to have unpleasant dreams, or to be aroused 
from their unquiet slumber by colic pains. In such in- 
stances, the brain becomes partially dormant, and does not 
impart to the digestive organs the requisite amount of nervous 
influence. The nervous stimulus being deficient, the unchanged 
food remains in the stomach, causing irritation of this organ. 

Illustration. A healthy farmer, who was in the habit of 
eating one fourth of a mince pie immediately before going to 
bed, became annoyed with unpleasant dreams, and, among the 
varied images of his fancy, he saw that of his deceased father. 
Becoming alarmed, he consulted a physician, who, after a 
patient hearing of the case, gravely advised him to eat half of 
a mince pie, assuring him that he would then see his grand- 
father. 

322. When the general system and digestive organs are 
enfeebled, mild, unstimulating food, in small quantities, should 
be given. In the instance of a shipwrecked and famished 
mariner, or a patient recovering from disease, but a small 
quantity of nourishment should be given at a time. The reason 
for this, is, that when the stomach is weakened from want 
of nourishment, it is as unfitted for a long period of action in 

321. What is the effect of eating immediately before retiring for sleep ? 
How is this illustrated in the case of a healthy farmer ? 322. How should 
the food be given when both the digestive organs and general system are 
debilitated ? Give the reason. 

13* 



150 ANATOMY, PHYSIOLOGY, AND HYGIENE. 

digesting food, as the muscles are, under like circumstances, 
for walking. Consequently, knowledge and prudence should 
direct the administration of food under these circumstances. 
The popular adage, that " food never does harm when there 
is a desire for it," is untrue, and, if practically adopted, may 
be injurious and destructive to life. 

Observation. Liquids are rapidly removed from the stom- 
ach by absorption. Hence, in cases of great prostration, 
when it is desirable to introduce nutriment into the system, 
without delay, the animal and vegetable broths are a desirable 
and convenient form of supplying aliment. 

323. The condition of the skin exercises an important in- 
fluence on the digestive apparatus. Let free perspiration be 
checked, either from uncleanliness or from chills, and it will 
diminish the functional action of the stomach and its asso- 
ciated organs. This is one of the fruitful causes of the 
" liver and stomach complaints " among the half-clothed and 
filthy population of the crowded cities and villages of our 
country. Attention to clothing and bathing would likewise 
prevent many of the diseases of the alimentary canal, called 
" season complaints," particularly among children. 

324. Restricting the movements of the ribs and diaphragm 
impairs digestion. At each full inspiration, the ribs are 
elevated, and the central portion of the diaphragm is depressed, 
from one to two inches. This depression is accompanied by a 
relaxation of the anterior abdominal walls. At each act of 
expiration, the relaxed abdominal muscles contract, the ribs 
are depressed, the diaphragm relaxes, and its central parts 
ascend. These movements of the midriff cause the elevation 
and depression of the .stomach, liver, and other abdominal 
organs, which is a natural stimulus of these parts. 

In cases of great prostration, what is recommended ? 323. How is 
the influence that the skin exercises on the digestive organs illustrated ? 
324. What effect on the digestive process has the restriction of the ribs 
and diaphragm ? 



HYGIENE OF THE DIGESTIVE ORGANS. 151 

325. It is noted of individuals who restrain the free move- 
ments of the abdominal muscles by tight dresses, that the tone 
and vigor of the digestive organs are diminished. The 
restricted waist will not admit of a full and deep inspiration ; 
and so essential is this to health, that abuse in this respect 
soon enfeebles and destroys the functions of the system. 

326. Pure air is necessary to give a keen appetite and 
vigorous digestion. The digestive organs not only need the 
stimulus of blood, but they absolutely need the influence of 
pure blood, which cannot exist in the system, except when we 
breathe a pure air. From this we leam why those persons 
who sleep in small, ill ventilated rooms, have little or no 
appetite in the morning, and why the mouth and throat are so 
dry and disagreeable. The effect of impure blood, in dimin- 
ishing the desire for food, and enfeebling the digestive organs, 
is well illustrated by the following incidents. 

Illustrations. 1st. Dr. Reid, in his work on " Ventilation 
of Rooms," relates that an innkeeper in London, when he 
provided a public dinner, always spread his tables in an 
under-ground room, with low walls, where the air was con- 
fined and impure. He assigned as a reason for so doing, that 
his guests consumed only one third as much food and wine, 
as if the tables were laid in the open air. 

2d. A manufacturer stated before a committee of the 
British Parliament, that he had removed an arrangement for 
ventilating his mill, because he noticed that his men ate much 
more after his mill was ventilated, than previous to admitting 
fresh air into the rooms, and that he could not afford to have 
them breathe pure air. 

Observation. Many of the ca^es of indigestion among 
clergymen, seamstresses, school teachers, sedentary me- 

325. "What is observed of those individuals that restrict the movements 
of the abdominal muscles ? 326. Why is pure air necessary to vigorous 
digestion ? Give illustration 1st. Illustration 2d. "What is one cause of 
indigestion among the sedentary class in community ? 



152 ANATOMY, PHYSIOLOGY, AND HYGIENE. 

chanics, and factory operatives, are produced by breathing 
the impure air of the rooms they occupy. These cases can 
be prevented, as well as cured, by proper attention to 
ventilation. 

327. The position of a person, in standing or sitting, 
exerts an influence upon the digestive organs. If a person 
lean, or stoop forward, the distance between the pelvic bones 
and the diaphragm is diminished. This prevents the de- 
pression of the diaphragm, while the stomach, liver, pancreas, 
and other abdominal organs, suffer compression, which induces 
many severe diseases of these organs. As healthy and well- 
developed muscles keep the spinal column in an erect position, 
which conduces to the health of the organs of digestion, the 
child should be taught to avoid all positions but the erect, while 
studying or walking. This position, combined with unre- 
stricted waists, will do much to remove the now prevalent 
disease, dyspepsia. 

328. Whatever kind of aliment is taken, it is separated 
into nutriment and residuum ; the former of which is con- 
veyed, through the medium of the circulation, to all organs 
of the system, and the latter, if not expelled, accumulates, 
causing headache and dizziness, with a general uneasiness ; 
and, if allowed to continue, it lays the foundation of a long 
period of suffering and disease. For the preservation of 
health, it is necessary that there should be a daily evacuation 
of the residual matter. 

Observation. In chronic diseases of the digestive organs, 
very frequently, there is an inactive, or costive condition of 
the alimentary canal. This may be removed in many cases, 
and relieved in all instances, by friction over the abdominal 
organs, and by making an effort at some stated period each 
day, (evening is best,) to evacuate the residuum. In acute 

327. Why does the position of a person affect digestion ? 328. Into 
what are different kinds of aliment separated ? 



HYGIENE OF THE DIGESTIVE ORGANS. 153 

diseases, as fever, regard should be given to regularity in 
relieving the intestines of residuum. Attention to this sug- 
gestion will obviate the necessity of cathartic medicine. 

329. We would add, for the benefit of those afflicted with 
hemorrhoids, or piles, that the best time for evacuating the 
intestinal canal would be immediately before retiring for the 
night. During the night, while recumbent, the protruding 
parts return to their proper place, and the surrounding organs 
acquire increased tone to retain them. The same observance 
will do much to prevent such prostrating diseases.* 

330. To recapitulate : digestion is most perfect when the 
action of the cutaneous vessels is energetic ; the brain and 
vocal organs moderately stimulated by animated conversa- 
tion ; the blood well purified ; the muscular system duly 
exercised ; the food of an appropriate quality, taken in proper 
quantities, at regular periods, and also properly masticated. 



* The urinary organs, as well as the intestinal canal, should be 
frequently and regularly evacuated. Some most distressing and 
frequently incurable complaints are caused by false customs and 
false delicacy in this particular. Teachers should be particularly 
careful, and regard this suggestion in reference to young pupils. 

330. Give the summary when digestion is most perfect. 



154 ANATOMY, PHYSIOLOGY, AND HYGIENE. 



CHAPTER XVII. 

THE CIRCULATORY ORGANS. 

331. The ultimate object of the food and drink introduced 
into the body, is to furnish material to promote the growth 
and repair the waste of the organs of the system. The for- 
mation of chyle (the nutrient portion of the food) has been 
traced through the digestive process, and its transfer into the 
vein at the lower part of the neck, from which it is conveyed 
to the heart; and, finally, in the lungs it assimilates to the 
character of blood. 

332. The blood, after standing a short time, when drawn 
from its vessels, separates into se'rum, (a watery fluid,) and 
co-ag'u-lum, (clot.) This fluid is distributed to every part of 
the system. There is no part so minute that it does not 
receive blood. The organs by which this distribution is 
effected are so connected that there is properly neither begin- 
ning nor end ; but as it respects their functions, they are con- 
nected in a complete circle. From this circumstance, they 
are called the Circulatory Organs. 

ANATOMY OF THE CIRCULATORY ORGANS. 

333. The circulatory organs are the Heart, Ar'te-ries, 
Veins, and Cap'il-la-ries. 

334. The heart is placed obliquely, in the left cavity of 
the chest, between the right and left lung. Its general form 

331. What is the ultimate object of the food ? 332. Of what is the blood 
composed ? What is said of the distribution of the blood ? 333. Name 
the circulatory organs. 334 — 351. Give the anatomy of the circulatory 
organs. 334. fe Describe the heart. 



ANATOMY OF THE CIRCULATORY ORGANS. 



155 



is that of an inverted cone, the base of which is directed 
upward and backward, toward the right shoulder, while its 
apex points forward to the left side, about three inches from 
the sternum to the space between the fifth and sixth ribs. Its 
under side rests upon the tendinous portion of the diaphragm. 
The heart is surrounded by a sac, called the per-i-car'di-um, 
(heart-case.) The interior surface of this membrane secretes 
a watery fluid, that lubricates the exterior of the heart, and 
obviates friction between it and the pericardium. 




Fig. 67. 




Fig. 66. A front view of the heart. 1, The right auricle of the heart. 2, The 
left auricle. 3, The right ventricle. 4, The left ventricle. 5, 6, 7, 8, 9, 10, The 
vessels* through which the blood passes to and from the heart. 

Fig. 67. A back view of the heart. 1, The right auricle. 2, The left auricle. 
3, The right ventricle. 4, The left ventricle. 5, 6, 7, The vessels that carry Ihe 
blood to and from the heart. 9, 10, 11, The nutrient vessels of the heart. 

Observation. In health, there is usually about a tea-spoon- 
ful of fluid in the pericardium. When these parts are dis- 
eased, it may be thrown out more abundantly, and sometimes 



* All vessels that carry blood to the heart, are called veins. 
vessels that carry blood from the heart, are called arteries. 



All 



"With, what is it surrounded ? What is its use ? How much fluid does 
this membrane contain when healthy ? 



156 ANATOMY, PHYSIOLOGY, AND HYGIENE. 

amounts to several ounces, producing a disease called dropsy 
of the heart. But all the unpleasant sensations in the region 
of the heart are not caused by an increased amount of fluid in 
the pericardium, as this disease is not of frequent occurrence. 
335. The heart is composed of muscular fibres, that 
traverse it in different directions, some longitudinally, but 
most of them in a spiral direction. The human heart is a 
double organ, or it has two sides, called the right and the left. 
The compartments of the two sides are separated by a mus- 
cular sep'tum, or partition. Again, each side of the heart is 
divided into two parts, called the Au'ri-cle (deaf ear) and the 
Ven'tri-cle. 




Fig. 68. A section of the heart, showing its cavities and valves. 3, The right 
auricle. 4, The opening between the right auricle and right ventricle. 5, The right 
ventricle. 6, The tricuspid valves. 7, The pulmonary artery. 9, The semilunar 
valves of the pulmonary artery. 10, The septum between the right and left ventricle. 
12, The left auricle. 13, The opening between the left auricle and left ventricle. 
14, The left ventricle. 15, The mitral valves. 16, The aorta. 17, The semilunar 
valves of the aorta. 

336. The auricles differ in muscularity from the ventri- 
cles. Their walls are thinner, and of a bluish color. These 
cavities are a kind of reservoir, designed to contain the blood 
arriving by the veins. 

337. The ventricles not only have their walls thicker 
than the auricles, but they differ in their internal structure. 

335. Of what is the heart composed ? Give its divisions. 336. Describe 
the auricles. 337. Describe the ventricles. 



ANATOMY OF THE CIRCULATORY ORGANS. 157 

From the interior of these cavities arise fleshy columns, called 
co-lum'nce, car'ne-ce. The walls of the left ventricle are thicker 
and stronger than those of the right. 

338. The cavities in the right side of the heart are triangu- 
lar in shape ; those of the left, oval. Each cavity will con- 
tain about two ounces of blood. Between the auricle and 
ventricle in the right side of the heart, there are three folds, 
or doublings, of thin, triangular membrane, called the tri-cus'- 
pid valves. Between the auricle and ventricle in the left side, 
there are two valves, called the mi'tral. There are seen pass- 
ing from the floating edge of these valves to the columnar 
carneee, small white cords, called clwr'dce, ten'di-nce, which 
prevent the floating edge of the valve from being carried into 
the auricle. 

339. The right ventricle of the heart gives rise to the PuV- 
mo-na-ry artery ; the left ventricle, to a large artery called 
the A-ort'a. At the commencement of each of these arteries 
there are three folds of membrane, and from their shape, they 
are called sem-i-lu'nar valves. 

340. The heart is supplied with arteries and veins, which 
ramify between its muscular fibres, through which its nutrient 
blood passes. It has, likewise, a few lymphatics, and many 
small nervous filaments from the sympathetic system of nerves. 
This organ, in its natural state, exhibits but slight indications 
of sensibility, and although nearly destitute of the sensation of 
touch, it is yet, however, instantly affected by every painful 
bodily excitement, or strong mental emotions. 

Observation. To obtain a clear idea of the heart and its 
valves, it is recommended to examine this part of an ox or 

338. How do the cavities in the heart differ ? What is found between 
the auricle and ventricle in the right side of the heart ? How many valves 
in the left side, and their names ? Where are the tendinous cords, and 
what is their use ? 339. What vessels proceed from the ventricles ? What 
is said of their valves ? 340. With what is the heart supplied ? What is 
said of its sensibility ? How can an idea of the structure of the heart be 
obtained ? 

14 



158 ANATOMY, PHYSIOLOGY, AND HYGIENE. 

calf. In order that each ventricle be opened without mutilat- 
ing the fleshy columns, tendinous cords, and valves, cut on 
each side of the septum parallel to it. This may be easily 
found between the ventricles, as they differ in thickness. 

341. The arteries are the cylindrical tubes that convey 
the blood from the heart to every part of the system. They 
are dense in structure, and preserve, for the most part, the 
cylindrical form, when emptied of their blood, which is their 
condition after death. 

342. The arteries are composed of three coats. The 
external, or cellular coat, is firm and strong ; the middle, or 
fibrous coat, is composed of yellowish fibres. This coat is 
elastic, fragile, and thicker than the external coat. Its elas- 
ticity enables the vessel to accommodate itself to the quantity 
of blood it may contain. The internal coat is a thin, serous 
membrane, which lines the interior of the artery, and gives 
it the smooth polish which that surface presents. It is con- 
tinuous with the lining membrane of the heart. 

343. Communications between arteries are free and nu- 
merous. They increase in frequency with diminution in 
the size of the branches, so that through the medium of the 
minute ramifications, the entire body may be considered as 
one circle of inosculation. The arteries, in their distribution 
through the body, are enclosed in a loose, cellular investment, 
called a sheath, which separates them from the surrounding 
tissues. 

344. The pulmonary artery commences in front of the 
origin of the aorta. It ascends obliquely to the under surface 
of the arch of the aorta, where it divides into two branches, 
one of which passes to the right, the other to the left lung. 
These divide and subdivide in the structure of the lungs, and 
terminate in the capillary vessels, which form a net-work 

341. What are arteries ? 342, Give their structure. 343. What is said 
of the communications between the arteries ? In their distribution, how 
are they separated from the surrounding tissues ? 344. Describe the pul- 
monary artery. 



ANATOMY OF THE CIRCULATORY ORGANS. 



159 



around the air-cells, and become continuous with the minute 
branches of the pulmonary veins. This artery conveys the 
impure blood to the lungs, and, with its corresponding veins, 
establishes the lesser, or pulmonic circulation. 

He. 69. 




Fig. 69. t, The trachea, h, The heart, a, The aorta, p, The pulmonary artery. 
1, The branch of the pulmonary artery that divides in the left lung. 2, The branch 
that divides in the right lung. 

The divisions of this artery continue to divide and subdivide, until they become 
no larger than hairs in size. These minute vessels pass over the air-cells, represented 
by small dark points around the margin of the lungs. 

345. The aorta proceeds from the left ventricle of the 
heart, and contains the pure, or arterial blood. This trunk 
gives off branches, which divide and subdivide to their ulti- 
mate ramifications, constituting the great arterial tree which 
pervades, by its minute subdivisions, every part of the animal 
frame. This great artery and its divisions, with their return- 
ing veins, constitute the greater, or systemic circulation. 

What does this artery and its corresponding veins establish ? Explain 
fig. 69. 345. Describe the aorta. "What do this artery and its corre- 
sponding veins constitute ? 



160 ANATOMY, FHYSIOLOGY, AND HYGIENE. 

Fig. 70. 




Fig. 70. The aorta and its branches. 1, The commencement of the aorta. 
2, The arch of the aorta. 3, The carotid artery. 4, The temporal artery. 5, The 
subclavian artery. 6, The axillary artery. 7, The brachial artery. 8, The radial 
artery. 9, The ulnar artery. 10, The iliac artery. 11, The femoral artery. 12, The 
tibial artery. 13. The peroneal artery. 

346. The veins are the vessels which return the blood to 
the auricles of the heart, after it has been circulated by the 

"What does fig. 70 represent ? 346. "What are the veins ? 



ANATOMY OF THE CIRCULATORY ORGANS. 161 

arteries through the various tissues of the body. They are 
thinner and more delicate in structure than the arteries, so 
that when emptied of their blood, they become flattened and 
collapsed. The veins commence by minute radicles in the 
capillaries, which are every where distributed through the 
textures of the body, and coalesce to constitute larger and 
larger branches, till they terminate in the large trunks which 
convey the dark-colored blood directly to the heart. In diam- 
eter they are much larger than the arteries, and, like those 
vessels, their combined area would constitute an imaginary 
cone, the apex of which is placed at the heart, and the base 
at the surface of the body. 

347. The communications between the veins are more 
frequent than between the arteries, and take place between 
the larger as well as among the smaller vessels. The office of 
these inosculations is very apparent, as tending to obviate the 
obstructions to which the veins are peculiarly liable, from the 
thinness of their coats, and from inability to overcome great 
impediments by the force of their current. These tubes, as 
well as the arteries, are supplied with nutrient vessels, and it 
is to be presumed that nervous filaments from the sympathetic 
nerves are distributed to their coats. 

348. The external, or cellular coat of the veins, is dense 
and firm, resembling the cellular tunic of the arteries. The 
middle coat is fibrous, like that of the arteries, but extremely 
thin. The internal coat is serous, and also similar to that of 
the arteries. It is continuous with the lining membrane of the 
heart at one extremity, and with the lining membrane of the 
capillaries at the other. 

349. At certain intervals, the internal coat forms folds, or 



Where do they commence ? 347. What is said of their communica- 
tions ? What is the apparent design of the inosculations of the veins ? 
What vessels are distributed to the coats of the veins ? 348. Give the 
structure of the coats of the veins. 349. How are the valves in the 
veins formed ? 

14* 



162 



ANATOMY, PHYSIOLOGY, AND HYGIENE. 



duplicates, which constitute .valves. They are generally com- 
posed of two semilunar folds, one on each side of the vessel. 
The free extremity of the valvular folds is concave, and 
directed forward, so that while the current of blood sets toward 
the heart, they present no impediment to its free passage ; but 
let the current become retrograde, and it is impeded by their 
distention. The valves are most numerous in the veins of the 
extremities, particularly the deeper veins situated between the 
muscles ; but in some of the larger trunks, and also in some 
of the smaller veins, no valves exist. 

Fig. 71. 




Fig. 71. A vein laid open to show the valves. 1, The trunk of the vein. 2, 2, Its 
valves. 3, An opening of a branch into the main trunk. 



What is their use ? "Where are they the most numerous ? 



ANATOMY OF THE CIRCULATORY ORGANS. 



163 



350. The capillaries constitute a microscopic net-work, 
and are so distributed through every part of the body as to 
render it impossible to introduce the smallest needle beneath 
the skin, without wounding several of these fine vessels. 
They are remarkable for the uniformity of diameter, and for 
the constant divisions and communications which take place 
between them. 

351. The capillaries inosculate, on the one hand, with the 
terminal extremity of the arteries, and on the other, with the 
commencement of the veins. They establish the communi- 
cation between the termination of the arteries and the begin- 
ning of the veins. The important operations of secretion 
and the conversion of the nutrient materials of the blood into 
bone, muscle, &c, are performed in these vessels. 



Fig. 72. 



Fig. 73. 





Fig. 72. An ideal view of a portion of the pulmonic circulation. 1, 1, A branch of 
the artery that carries the impure blood to the lungs. 3, 3, Capillary vessels. 2, 2, A 
vein through which red blood is returned to the left side of the heart. 

Fig. 73. An ideal view of a portion of the systemic circulation. 1,1, A branch 
of the aorta. This terminates in the capillaries, (3, 3.) 2, 2, A vein through which 
the impure blood is carried to the right side of the heart. 



350. What do the capillaries constitute ? For what are they remark- 
able ? 351. What relation do they bear to the arteries and veins ? What 
important operations are performed in these vessels ? What is represented 
by fig. 72 ? By fig. 73 ? 



164 ANATOMY, PHYSIOLOGY, AND HYGIENE. 



CHAPTER XVIII. 

PHYSIOLOGY OF THE CIRCULATORY ORGANS. 

352. The walls of all the cavities of the heart are com- 
posed of muscular fibres, which are endowed with the 
property of contracting and relaxing, like the muscles of the 
extremities. The contraction and relaxation of the mus- 
cular tissue of the heart, produce a diminution and en- 
largement of both auricular and ventricular cavities. The 
right and left auricles contract simultaneously. When these 
contract, the right and left ventricles dilate. The dilatation of 
the ventricles is termed the di-as'to-le of the heart ; their con- 
traction, its sys'to-le. 

353. The ventricles contract quicker and more forcibly 
than the auricles, and they are three times longer in dilating 
than contracting. The walls of the right ventricle, being 
thinner than the left, are more distensible, and thus this cavity 
will contain a greater amount of blood. This arrangement 
adapts it to the venous system, which is more capacious than 
the arterial. The thicker and more powerful walls of the 
left ventricle adapt it to expel the blood to a greater distance. 

354. The valves in the heart permit the blood to flow from 
the auricles to the ventricles, but prevent its renewing. The 
valves at the commencement of the aorta and pulmonary 

352 — 366. Give the physiology of the circulatory organs. 352. What do 
the contraction and relaxation of the muscular walls of the heart 
produce ? How do the auricles and ventricles contract and dilate ? 
353. What is said of the contraction and dilatation of the ventricles in 
the heart ? How is the right ventricle adapted to its function ? How 
the left ? 354. What is the use of the valves in the heart ? Those of 
the aorta and pulmonary artery ? 



PHYSIOLOGY OF THE CIRCULATORY ORGANS. 165 

artery, permit the blood to flow from the ventricles into these 
vessels, but prevent its returning. 

, 355. The function of the different parts of the heart, 
will be given, by aid of fig. 74. The blood passes from the 
right auricle (3) into the right ventricle, (5,) and the tricuspid 
valves (6) prevent its reflux ; from the right ventricle the 
blood is forced into the pulmonary artery, (7,) through which 
it passes to the lungs. The semilunar valves (9) prevent 
this circulating fluid returning to the ventricle. The blood, 
while passing over the air-cells in the lungs, in the minute 
divisions of the pulmonary artery, is changed from a bluish 
color to a bright red. It is then returned to the left auricle 
of the heart by the pulmonary veins, (11, 11.) 

Fig. 74. 




Fig. 74. 1, The descending vena cava, (vein.) 2, The ascending vena cava, (vein.) 
3, The right auricle. 4, The opening between the right auricle and the right ventri- 
cle. 5, The right ventricle. 6, The tricuspid valves. 7, The pulmonary artery. 

8, 8, The blanches of the pulmonary artery that pass to the right and left lung. 

9, The semilunar valves of the pulmonary artery. 10, The septum between the two 
ventricles of the heart. 11, 11, The pulmonary veins. 12, The left auricle. 13, The 
opening between the left auricle and ventricle. 14, The left ventricle. 15, The 
mitral valves. 16, 16, The aorta. 17, The semilunar valves of the aorta. 

355. Describe the course of the blood from the right auricle in the heart 
to the lungs. 



166 ANATOMY, PHYSIOLOGY, AND HYGIENE. 

Observation. If the blood is not changed in the lungs, it 
will not flow to the pulmonary veins. This phenomenon is 
seen in instances of death from drowning, strangling, carbonic 
acid, &c. The same is true, but in a less degree, of indi- 
viduals whose apparel is tight, as well as of those who breathe 
impure air, or have diseased lungs. 

356. The left auricle, (12,) by its contraction, forces the 
blood into the left ventricle, (14.) The mitral valves (15) pre- 
vent its reflowing. From the left ventricle the blood is forced 
into the aorta, (16,) through which, and its subdivisions, it is 
distributed to every part of the system. The semilunar valves 
(17) prevent its returning. 

Observation. The parts of the circulatory organs most 
liable to disease are the valves of the heart, particularly the 
mitral. When these membranous folds become ossified or 
ruptured, the blood regurgitates, and causes great distress in 
breathing. The operations of the system are thus disturbed, 
as the movements of the steam engine would be if its valves 
were injured, or did not play freely. 

357. The difference between the functions of the pulmo- 
nary artery and aorta is, the former communicates with the 
right ventricle of the heart, and distributes only impure blood 
to the lungs ; the other connects with the left ventricle of the 
heart, and distributes pure blood to the whole body, the lungs 
not excepted. At the extremity of the divisions of the aorta, 
as well as the pulmonary artery, are found capillary vessels. 
This curious net-work of vessels connects with the minute 
veins of the body, which return the blood to the heart. 

Observation. The function of the veins of the systemic 

"What is the effect when the blood is not changed in the lungs ? 
356. Describe the circulation of the blood from the left auricle to the 
general system. "What part of the circulatory organs is most liable to 
disease ? What is the effect when the valves are diseased ? 357. Give the 
difference in the functions of the pulmonary artery and aorta. Show the 
relation between the functions of the arteries and veins both of the pul- 
monic and svstemic circulation. 



PHYSIOLOGY OF THE CIRCULATORY ORGANS. 167 

circulation is similar to the office Of the arteries in the lungs, 
and that the veins of the pulmonic circulation transmit to the 
heart the pure, or arterial blood, and thus resemble in their 
function the- arteries of the general system. 

358. The veins that receive the blood from all parts of the 
body, follow nearly the same course as the arteries. The 
myriads of these small vessels beneath the skin, and others 
that accompany the arteries, at last unite and form two large 
trunks, called ve'na ca'va as-cend'ens, and descend' ens. 

Observation. A peculiarity is presented in the veins which 
come from the intestines. After forming a large trunk, they 
enter the liver, and ramify like the arteries, and in this organ 
they again unite into a trunk, and enter the ascending vein, 
or cava, near the heart. 

359. The ventricles of the heart contract, or the " pulse " 
beats, about seventy-five times every minute, in adults ; in 
infants, more than a hundred times every minute ; in old 
persons, less than seventy-five times every minute. The 
energy of the contraction of this organ varies in different 
individuals of the same age. It is likewise modified by the 
health and tone of the system. It is difficult to estimate the 
muscular power of the heart ; but, comparing it with other 
muscles, and judging from the force with which blood is 
ejected from a severed artery, it must be very great. 

Observation. The phenomenon known under the name of 
pulse, is the motion caused by the pressure of the blood 
against the coats of the arteries at each contraction of the 
ventricles. 

360. The following experiment will demonstrate that the 
blood flows from the heart. Apply the fingers upon the artery 

358. What is the course of the veins ? "What peculiarity is observable 
in the veins of the liver ? 359. How often does the heart contract, or the 
pulse beat, in adults ? In infants ? In old persons ? What is said of the 
energy of its contraction in different persons ? How is the pulse produced ? 
360. Demonstrate by experiment that the blood flows from the heart. 



168 ANATOMY, PHYSIOLOGY, AND HYGIENE. 

at the wrist, at two different points, about two inches apart ; 
if the pressure be moderately made, the " pulse " will be felt 
at both points. Let the point nearest the heart be pressed 
firmly, and there will be no pulsation at the lower point ; but 
make strong pressure upon the lower point only, and the pul- 
sation will continue at the upper point, proving that the blood 
flows from the heart, in the arteries, to different parts of the 
system. 

361. There are several influences, either separately or 
combined, that propel the blood from the heart through the 
arteries, among which may be named, — 1st. The contraction 
of the muscular walls of the heart. 2d. The contractile and 
elastic middle coat of the arteries aids the heart in impelling 
the blood to the minute vessels of the system. 3d. The 
peculiar action of the minute capillary vessels is considered, 
by some physiologists, as a motive power in the arterial circu- 
lation. 4th. The pressure of the muscles upon the arteries, 
when in a state of contraction, is a powerful agent, particu- 
larly when they are in active exercise. 

362. The following experiments will demonstrate that the 
blood from every part of the system flows to the heart by the 
agency of the veins. 1st. Press firmly on one of the veins 
upon the back of the hand, carrying the pressure toward the 
fingers ; for a moment, the vein will disappear. On remov- 
ing the pressure of the finger, it will reappear, from the blood 
rushing in from below. 

2d. If a tape be tied around the arm above the elbow, the 
veins below will become larger and more prominent, and also 
a greater number will be brought in view, while the veins 
above the tape are less distended. At this time, apply the fin- 
ger at the wrist, and the pulsation of the arteries still continues, 
showing that the blood is constantly flowing from the heart 

361. State the influences that propel the blood from the heart. 362. De- 
monstrate by the first experiment that the blood flows to the heart. By the 
second experiment. 



PHYSIOLOGY OF THE CIRCULATORY ORGANS. 169 

through the arteries, into the veins ; and the increased size of 
the veins shows that the pressure of the tape prevents its 
flowing back to the heart. 

363. The influences that return the blood to the heart through 
the veins, are not so easily understood as those that act on the 
blood in the arteries. Some physiologists have imputed an 
active propulsive power to the capillary vessels in carrying 
the blood through the veins. This is not easily explained, 
and perhaps it is as difficult to understand. An influence 
upon which others have dwelt, is the suction power of the 
heart in active dilatation, acting as a vis afronte (power in 
front) in drawing blood to it. 

364. Another influence that aids the venous circulation is 
attributed to the propulsive power of the heart. It is not 
easy to comprehend how this power of the heart can be 
extended through the capillary vessels to the blood in the 
veins. Again, au important agency has been found, by some 
physiologists, in the inspiratory movements, which are sup- 
posed to draw the blood of the veins into the chest, in order 
to supply the vacuum which is created there by the elevation 
of the ribs and the descent of the diaphragm. 

365. One of the most powerful causes which influence the 
venous circulation, is the frequently-recurring action of the 
muscles upon the venous trunks. When the muscles are 
contracted, they compress that portion of the veins which lie 
beneath the swell, and thus force the blood from one valve to 
the other, toward the heart. When they are relaxed, the 
veins refill, and are compressed by the recurring action of 
the muscles. 

Observation. The physician, in opening a vein, relies on 
the energetic contractions and sudden relaxations of the 

363. "What is said of the influences that return the blood to the heart ? 
What is said of the propulsive power of the capillaries ? Of the suction 
power of the heart ? 364. Give another influence. State another agency. 
365. What is one of the most powerful causes which influence venous 
circulation ? <Kve practical observation. 
15 



170 ANATOMY, PHYSIOLOGY, AND HYGIENE. 

■Fig. 75. 




Fig 75. An ideal view of the circulation in the lungs and system. From the right 
ventricle of the heart, (2,) the dark, impure blood is forced into the pulmonary 
artery, (3,) and its branches (4, 5) carry the blood to the left and right lung. In 
the capillary vessels (G, 6) of the lungs, the blood becomes pure, or of a red color, 
and is returned to the left auricle of the heart, (9,) by the veins, (7, 8.) From the 
left auricle the pure blood passes into the left ventricle, (10.) By a forcible contrac- 
tion of the left ventricle of the heart, the blood is thrown into the aorta, (11.) It3 
branches (12, 13, 13) carry the pure blood to every organ or part of the body. The 
divisions and subdivisions of the aorta terminate in capillary vessels, represented by 
14, 14. In these hair-like vessels the blood becomes dark colored, and is returned 
to the right auricle of the heart (1) by the vena cava descendens, (15,) and vena 
cava ascendens, (16.) The tricuspid valves (17) prevent the reflow of the blood from 
the right ventricle to the right auricle. The semilunar valves (18) prevent the blood 
passing from the pulmonary artery to the right ventricle. The mitral valves (19) pre- 
vent the reflow of blood from the left ventricle to the left auricle. The semilunar 
valves (20) prevent the reflow of blood from the aorta to the left ventricle. 



PHYSIOLOGY OF THE CIRCULATORY ORGANS. 171 

muscles, when he directs the patient to clasp the head of a 
cane, or the arm of a chair ; these alternate motions of the 
muscles cause an increased flow of blood to the veins of the 
ligated arm. 

366. The muscles exercise an agency in maintaining the 
venous circulation at a point above what the heart could per- 
form. As the pulsations are diminished by rest, so they are 
accelerated by exercise, and very much quickened by violent 
effort. There can be little doubt that the increased rapid- 
ity of the return of blood through the veins, is, of itself, a 
sufficient cause for the accelerated movements of the heart, 
during active exercise. 

Observation. The quantity of blood in different individuals 
varies. From twenty-five to thirty-five pounds maj be consid- 
ered an average estimate in a healthy adult of medium size. 
The time in which the blood courses through the body and 
returns to the heart, is different in different individuals. Many 
writers on physiology unconditionally limit the period to three 
minutes. It is undeniable that the size and health of a per- 
son, the condition of the heart, lungs, and brain, the quantity 
of the circulating fluid, the amount and character of the 
inspired air, and the amount of muscular action, exert a mod- 
ifying influence. The time probably varies from three to 
eight minutes. 

366. "What causes the accelerated movements of the heart during active 
exercise ? 

Note. Let the pupil review the anatomy and physiology of the circula- 
tory organs from fig. lb, or from anatomical outline plates, No. 6 and 7. 



172 ANATOMY, PHYSIOLOGY, AND HYGIENE. 



CHAPTER XIX. 

HYGIENE OF THE CIRCULATORY ORGANS. 

367. If any part of the system is deprived of blood, its 
vitality will cease ; but, if the blood is lessened in quantity to 
a limited extent, only the vigor and health of the part will be 
impaired. The following conditions, if observed, will favor 
the free and regular supply of blood to all portions of the 
system. 

368. The clothing should be loosely worn. Compression 
of any kind impedes, the passage of blood through the vessels 
of the compressed portion. Hence, no article of apparel 
should be worn so as to prevent a free flow of blood through 
every organ of the body. 

369. The blood which passes to and from the brain, flows 
through the vessels of the neck. If the dressing of this part 
of the body is close, the circulation will be impeded, and the 
functions of the brain will be impaired. This remark is par- 
ticularly important to scholars, public speakers, and individu- 
als predisposed to apoplexy, and other diseases of the brain. 

370. As many of the large veins lie immediately beneath 
the skin, through which the blood is returned from the lower 
extremities, if the ligatures used to retain the hose, or any 
other article of apparel, in proper position, be tight and 
inelastic, the passage of blood through these vessels will be 



367 — 386. Give the hygiene of the circulatory organs. 367. What effect 
will be produced on the body if it is deprived of blood ? If the blood is 
only lessened in quantity ? 368. Why should the clothing be worn loose ? 
369. What is said of dressing the neck ? To what persons is this remark 
applicable ? 370. How are enlarged veins frequently produced ? 



HYGIENE OF THE CIRCULATORY ORGANS. 173 

obstructed, producing, by their distention, the varicose, or 
enlarged veins. Hence elastic bands should always be used 
for these purposes. 

371. An equal temperature of all parts of the system pro- 
motes health. A chill on one portion of the body diminishes 
the size of its circulating vessels, and the blood which 
should distend and stimulate the chilled part, will accumulate 
in other organs. The deficiency of blood in the chilled portion 
induces weakness, while the superabundance of sanguineous 
fluid may cause disease in another part of the system. 

372. The skin should be kept not only of an equal, but at its 
natural temperature. If the skin is not kept warm by adequate 
clothing, so that chills shall not produce a contraction of the 
blood-vessels and a consequent paleness, the blood will recede 
from the surface of the body, and accumulate in the internal 
organs. Cleanliness of the skin is likewise necessary, for the 
reason, that this condition favors the free action of the cutane- 
ous vessels. 

Observation. When intending to ride in a cold day, wash 
the face, hands, and feet, in cold water, and rub them smartly 
with a coarse towel. This is far better to keep the extrem- 
ities warm, than to take spirits into the stomach. 

373. Exercise promotes the circulation of the blood. As 
the action of the muscles is one of the important agents which 
propel the blood through the arteries and veins, daily and 
regular exercise of the muscular system is required to sustain 
a vigorous circulation in the extremities and skin, and also to 
maintain a healthy condition of the system. The best stimu- 
lants to improve the sluggish circulation of an indolent patient, 
whose skin is pale and whose extremities are cold, are the 

371. "Why should the temperature of the body be equal ? 372. "Why 
should the skin be kept at its natural, as well as at an equal temperature ? 
"What practical observation when intending to ride in a cold day ? 373. Why 
does exercise promote health ? "What are good stimulants for sluggish 
circulation in the indolent ? 

15* 



174 ANATOMY, PHYSIOLOGY, AND HYGIENE. 

union of vigorous muscular exercise with agreeable mental 
action, and the systematic application to the skin of cold 
water, attended with friction. 

Illustration. The coach-driver and teamster throw their 
arms around their bodies to warm them when cold. The 
muscles that are called into action in swinging the arms, force 
a greater quantity of blood into the chilled parts, and, conse- 
quently, more heat is produced. 

374. When a number of muscles are called into energetic 
action, a greater quantity of blood will be propelled to the 
lungs and heart in a given time, than when the muscles are 
in a state of comparative inaction. It is no uncommon occur- 
rence, that before there is a proper expansion of the respira- 
tory organs to correspond with the frequency and energy of 
the movements of the muscles, there is an accumulation of 
blood in the lungs, attended by a painful sensation of fulness 
and oppression in the chest, with violent and irregular action 
of the heart. This condition of the organs of the chest, called 
congestion, may be followed by cough, inflammation of the 
lungs, asthma, and a structural disease of the heart. 

375. To avoid these sensations and results, when we feel 
necessitated to walk or run a considerable distance in a short 
time, commence the movements in a moderate manner, 
increasing the speed as the respiratory movements become 
more frequent and their expansion more extensive, so that a 
sufficient amount of air may be received into the lungs to 
purify the increased quantity of blood forced into them. The 
same principles should be observed when commencing labor, 
and in driving horses and other animals. 

Observation. When a large number of muscles are called 
into action after repose, as when we rise from a recumbent or 

Mention the illustration. 374. What is the effect when a number of 
muscles are called into energetic action ? What effect has this accumu- 
lation of blood in the lungs ? 375. How can such disagreeable sensations 
be avoided ? Mention a practical observation. 



HYGIENE OF THE CIRCULATORY ORGANS. 175 

sitting posture, the blood is impelled to the heart with a very- 
strong impetus. If that organ should be diseased, it may 
arrive there in larger quantities than can be disposed of, and 
death may be the result. Hence the necessity of avoiding all 
sudden and violent movements, on the part of those who have 
either a functional or structural disease of the heart. 

376. The mind exercises no inconsiderable influence upon 
the circulatory organs. When an individual is stimulated by 
hope, or excited by anger, the heart beats more forcibly, and 
the arteries act more energetically, than when a person is 
influenced by fear, despair, or sorrow. Consequently, the 
system is more fully nourished, and capable of greater exer- 
tion, when the former condition obtains, than when the latter 
exists. 

377. The quality and quantity of the blood modify the 
action of the heart and blood-vessels. If this fluid is 
abundant and pure, the circulatory vessels act with more 
energy than when it is deficient in quantity or defective in 
quality. 

Illustrations. 1st. In an athletic man, whose heart beats 
forcibly, and whose pulse is strong, if a considerable quantity 
of blood is drawn from a vein, as in bleeding, the heart will 
beat feebly, and the pulse will become weak. 
• 2d. When the blood is made impure by inhaling vitiated air, 
the action of the heart and arteries is diminished, which pro- 
duces an effect similar to that which takes place when blood 
is drawn from a vein. 

378. Hemorrhage from divided arteries should be imme- 
diately arrested. When large blood-vessels are wounded or 
cut, the flow of blood must be immediately stopped, or the 
person soon faints, and the heart ceases its action. If it is a 

376. State some of the effects that the mind has on circulation. 
377. What effect have the quantity and quality of blood upon the circu- 
latory organs ? Give illustration 1st. Illustration 2d. 378. What is 
necessary when large blood-vessels are wounded or cut ? 



176 



ANATOMY, PHYSIOLOGY, AND HYGIENE. 



large artery that is wounded, the blood will be thrown out in 
jets, or jerks, every time the pulse beats. The flow of blood 
can be stopped until a surgeon arrives, either by compressing 
the vessel between the wound and the heart, or by compress- 
ing the end of the divided artery in the wound. 



Fig. 77. 




Fig. 76. The track of the large artery of the arm. 1, The collar-bone. 9 
axillary artery. 10, The brachial artery. 

Fig. 77. B, The manner of compressing the artery near the collar-bone. A 
manner of compressing the large artery of the arm, with the fingers. C, The m 
of compressing the divided extremity of an artery in the wound, with a finger. 



, The 
anner 



379. After making compression with the fingers, as de- 
scribed and illustrated, take a piece of cloth or handkerchief, 
twist it cornerwise, and tie a hard knot midway between the 



What is shown by fig. 76 ? By fig. 77 ? 379. What is to be done after 
compressing the wound, as before described ? 



HYGIENE OF THE CIRCULATORY ORGANS. 



177 



two ends. This knot should be placed over the artery, be- 
tween the wound and the heart, and the ends carried around 
the limb and loosely tied. A stick, five or six inches long, 
should be placed under the handkerchief, which should be 
twisted until the knot has made sufficient compression on the 
artery to allow the removal of the fingers without a return 
Continue the compression until a surgeon can 



of bleeding, 
be called. 



Fis. 78. 



Fig. 79. 




Fig. 78. A, B, The track of the large artery of the arm. The figure exhibits the 
method of applying the knotted handkerchief to make compression on this artery. 



Fig. 79. A, C, The track of the large artery of the thigh, 
applying the knotted handkerchief to compress this arteiy. 



B, The method of 



380. When an artery of the arm is cut, elevating the 
wounded limb above the head will tend to arrest the flow of 
blood. In a wound of a lower limb, raise the foot, so that it 
shall be higher than the hip, until the bleeding ceases. 

Illustration. On one occasion, the distinguished Dr. Na- 
than Smith was called to a person who had divided one of 



"What is shown by fig. 78 and 79 ? 380. "What suggestion relative to 
the position of a limb when bleeding ? Relate a simple operation by 
Dr. Nathan Smith. 



178 ANATOMY, PHYSIOLOGY, AND HYGIENE. 

the large arteries below the knee. After trying in vain to 
find the bleeding vessel, so as to secure it, he caused the foot 
to be elevated higher than the hip. At the first instant the 
blood was forced from the wound about twelve inches ; in 
a minute, it was diminished to three or four ; and, in a 
short time, the bleeding ceased. This Dr. S. called his 
" great " operation ; and it was truly great in simplicity 
and science. • 

381. The practical utility of every person knowing the 
proper means of arresting hemorrhage from severed arteries, 
is illustrated by the following incidents. In 1848, in the town 
of N., Mass., a mechanic divided the femoral artery; although 
several adult persons were present, he died in a few minutes 
from loss of blood, because those persons were ignorant of the 
method of compressing severed arteries until a surgeon could 
be obtained. 

382. In 1846, a similar accident occurred in the suburbs 
of Philadelphia. While the blood was flowing copiously, a 
lad, who had received instruction on the treatment of such 
accidents at the Philadelphia High School, rushed through 
the crowd that surrounded the apparently dying man, 
placed his finger upon the divided vessel, and continued 
the compression until the bleeding artery was secured by a 
surgeon. 

383. In " flesh wounds," when no large blood-vessel is 
divided, wash the part with cold water, and, when bleeding 
has ceased, draw the incision together, and retain it with 
narrow strips of adhesive plaster. These should be put on 
smoothly, and a sufficient number applied to cover the wound. 
In most instances of domestic practice, the strips of adhesive 
plaster are too wide. They should not exceed in width one 

381. Relate the first incident showing the utility of every person know- 
ing the proper method of arresting the flow of blood from divided arte- 
ries. 382. The second incident. 383. How should "flesh wounds" be 
dressed ? 



HYGIENE OF THE CIRCULATORY ORGANS. 



179 



fourth of an inch. Then apply a loose bandage, and avoid 
all " healing salves," ointments, and washes. In removing 
the dressing from a wound, both ends of the strips of piaster 
should be raised and drawn toward the incision. The lia- 
bility of the wound re-opening is thus diminished. 

Observation. The union of the divided parts is effected by 
the action of the divided blood-vessels, and not by salves and 
ointments. The only object of the dressing is to keep the 
parts together, and protect the wound from air and impurities. 
Nature, in all cases of injuries, performs her own cure. Such 
simple wounds do not generally require a second dressing, 
and should not be opened until the incisions are healed. 

Fig. 80. 




Fig. 80. The manner in which strips of adhesive plaster are applied to wounds. 

384. In wounds made by pointed instruments, as a nail, or 
in lacerated wounds, as those made by forcing a blunt instru- 
ment, as a hook, into the soft parts, there will be no direct 
and immediate union. In these cases, apply a soothing poul- 
tice, as one made of linseed meal, and also keep the limb 
still. It is judicious to consult a physician immediately, in 
punctured or lacerated wounds, because they often induce 
the most dangerous diseases. 

385. Wounds caused by the bite of rabid animals or ven- 
omous serpents, should be immediately cleansed with pure 



What should be avoided ? How should the strips of plaster be removed 
from a wound ? How is the union of the divided parts effected ? 384. How 
should punctured and lacerated wounds be dressed? 385. What is the 
treatment of wounds caused by the bite of rabid animals ? 



180 ANATOMY, PHYSIOLOGY, AND HYGIENE. 

water. In many instances, the application of suction, either 
with " cupping glasses," or the mouth, will prevent the intro- 
duction of the poisonous matter into the system by absorption. 
When this is effected, cover the wound with a soothing 
poultice, as one made of slippery elm bark. 

Observation. Although animal poisons, when introduced 
into the circulating fluid through the broken surface of the 
skin, frequently cause death, yet they can be taken into the 
mouth and stomach with impunity, if the mucous membrane 
which lines these parts is not broken. 

Fig. 81. 



Fig. 81. a, a t Representation of wounds on the back part of the arm and fore-arm. 
b, b, Wounds on the anterior part of the arm and fore-arm. By bending the elbow 
and wrist, the incisions at a, a, are opened, while those at b, b, are closed. Were the 
arm extended at the elbow and wrist, the wounds at a, a, would be closed, and those 
at b, b, would be opened. 

386. The proper position of the .limbs favors the union of 
wounds. If the incision be upon the anterior part of the leg, 
between the knee and ankle, extending the knee and bending 
the ankle will aid its closing. If it be upon the back part of 
the leg, by extending the foot and bending the knee, the 
gaping of the incision will be diminished. When wounds 
occur upon the trunk or upper extremities, let the position of 
the person be regarded. 

386. Does the proper position of the limbs favor the union of wounds ? 



ANATOMY OF THE LYMPHATIC VESSELS. 181 



CHAPTER XX. 

ABSORPTION. 

387. Absorption is the process by which the materials of 
nutrition are removed from the alimentary canal, to be con- 
veyed into the circulatory vessels. It is likewise the process 
by which the particles of matter that have become injurious, 
or useless, are removed from the mass of fluids and solids 
of which the body is composed. These renovating and 
removing processes are performed by two sets of vessels. 

ANATOMY OF THE LYMPHATIC VESSELS. 

388. The vessels that act exclusively for the growth and 
renovation of the system, are found only in the alimentary 
canal. They are called lacteals. The vessels whose sole 
function is to remove particles of matter already deposited, 
are called Lym-phat'ics. The radicals, or commencement of 
the veins, in many, and it may be in all parts of the body, 
perform the office of absorption. 

Observation. This fact accounts for the capacity of the 
venous system exceeding the arterial. Had the veins no other 
function to perform, beside returning the blood that had been 
distributed by the arteries > it would be reasonable to suppose 
that this system would be less than the arterial, but the reverse 
is known to be true. 

389. The lymphatic vessels, in structure, resemble the 

387. Define absorption. 388 — 391. Give the anatomy of the lymphatic 
vessels. 388. "What are those vessels called that act exclusively for the 
growth and renovation of the body ? Those whose office is to remove the 
atoms already deposited ? "What other vessels perform the office of ab- 
sorption ? Give observation. 389. Describe the lymphatics. 

16 



182 ANATOMY, PHYSIOLOGY, AND HYGIENE. 

lacteals. They exist in great numbers in the skin and mucous 
membranes, particularly those of the lungs. Though no 
lymphatics have been traced to the brain, it is presumed that 
they exist there, as this part of the body is not exempt from 
the composition and decomposition, which are perpetual in 
the body. These vessels are extremely minute at their origin, 
so that in many parts of the system they cannot be detected 
without the aid of a microscope. 

Fig. 82. Fig. 83. Fig. 84. 




Fig. 82. A single lymphatic vessel, much magnified. 

Fig. 83. The valves of a lymphatic trunk. 

Fig. 84. 1, A lymphatic gland with several vessels passing through it. 

390. The lymphatic vessels, like the veins, diminish in 
number as they increase in size, while pursuing their course 
toward the large veins near the heart, into which they pour 
their contents. The walls of these vessels have two coats, 
of which the external one is cellular, and is capable of con- 
siderable distention. The internal coat is folded so as to form 

What is represented by fig. 82 ? By fig. 83 ? By fig. 84 ? 390. In what 
respect do these vessels resemble the veins of the system ? Give the 
structure of their coats. 



PHYSIOLOGY OF THE LYMPHATIC VESSELS. 183 

valves, like those in the veins. Their walls are so thin, that 
these folds give them the appearance of being knotted. 

391. At certain points, the lymphatic vessels pass through 
distinct, soft bodies, peculiar to themselves, which are called 
lymphatic glands, which are to these vessels what the mesen- 
teric glands are to the lacteals. The lymphatic glands vary 
in form and in size. They are extremely vascular, and 
appear to consist of a collection of minute vessels. These 
glands are found in different parts of the body, but are most 
numerous in the groins, axilla, or arm-pits, neck, and cavities 
of the chest and abdomen. 

Observation. From exposure to cold, these glands are 
frequently enlarged and inflamed. They are known under 
the name of " kernels." They are often diseased, particu- 
larly in scrofula, or " king's evil." 

PHYSIOLOGY OF THE LYMPHATIC VESSELS. 

392. Though the lacteals and lymphatics resemble each 
other in their structure and termination, yet they differ as to 
the nature of the fluids which they convey, as well as the 
nature of their functions. The lacteals open into the small 
intestine, and possess the power of rejecting all substances in 
the passing aliment, but the chyle. The lymphatics, on the 
contrary, not only imbibe all the various constituents of the 
body, both fluid and solid, when their vitality has ceased, but 
they absorb foreign and extraneous substances, when pre- 
sented to their mouths. 

393. The varieties of absorption are, the In-ter-sti'tial, 
Rec-re-men-ti'tial, Ex-cre-men-ti'tial, Cu-ta'ne-ous, Res-pi'ra- 
to-ry, Ve'nous, and the Lac'te-al. 

391. Describe the lymphatic glands. What observation is given in regard 
to these glands ? 392 — i03. Give the physiology of the lymphatic ves- 
sels. 392. Explain the difference between the lacteals and lymphatics. 
393. Name the varieties of absorption. 



184 ANATOMY, PHYSIOLOGY, AND HYGIENE. 

394. Interstitial absorption is that change which is con- 
stantly going on in the animal economy among the particles 
of matter of which every texture is composed. The ordinary 
functions of the body, in health, require incessant action of the 
lymphatics; the circulatory system, with its myriads of small 
vessels, is constantly depositing new atoms of matter, which 
become vitalized, and perform a course of actions, then die, 
or become useless. These old atoms are removed by the 
absorbent system. Thus, wherever there is a minute artery 
to deposit a living particle of matter, there is a lymphatic 
vessel, or venous radicle, to remove it as soon as it shall have 
finished its particular office. 

395. The action of the lymphatic vessels counterbalances 
those of nutrition, and thus the form and size of every part 
of the body is preserved. When their action exceeds that of 
the nutrient vessels, the body emaciates ; when it is deficient, 
plethora is the result. In youth, they are less active than the 
nutrient vessels, and the limbs are plump ; but in later periods 
of life, we find these actions reversed, and the body diminishes 
in size. It is not unfrequent that wens, and other tumors of 
considerable size, disappear, and even the entire bone of a 
limb has been removed from the same general cause. The 
effused fluids of bruises are also removed by absorption. 

Observations. 1st. When little or no food is taken into the 
stomach, life is supported by the lymphatic vessels and veins 
imbibing the fat and reconveying it into the blood-vessels. It is 
the removal of this secretion which causes the emaciation of 
the face and extremities of a person recovering from a fever. 
In consumption, the extreme attenuation of the limbs is caused 
by the absorption, not only of the fat, but also of the muscles 
and more solid parts of the system. 

394. What is interstitial absorption ? How are the new atoms of matter 
deposited ? How removed ? 395. What vessels do the lymphatics coun- 
terbalance in action ? What is the result when their action exceeds that 
of the nutrient vessels ? When it is less ? Mention some instances of 
active absorption. What causes the emaciated limbs of a person recovering 
from fever ? The extreme attenuation in consumption ? 



PHYSIOLOGY OF THE LYMPHATIC VESSELS. 185 

2d. Animals which live in a half torpid state during the 
winter, derive their nourishment from the same source. In 
other words, we may say the starving animal lives for a 
time upon itself, eating up, by internal absorption, such 
parts of the body as can be spared under urgent necessity, 
to feed these organs and continue those functions that are 
absolutely essential to life. 

396. Recrementitial absorption is the removal of those 
fluids from the system, which are secreted upon surfaces that 
have no external outlet. These fluids are various, as the fat, 
the marrow, the synovia of joints, serous fluids, and the humors 
of the eye. Were it not for this variety of absorption, dropsy 
would generally exist in the cavities of the brain, chest, and 
abdomen, from the continued action of the secretory vessels. 

397. Excrementitial absorption relates to the fluids which 
have been excreted, such as the bile, pancreatic fluid, saliva, 
milk, and other secretions. 

398. Cutaneous absorption relates to the skin. Here the 
lymphatic vessels extend only to the cuticle, which they do 
not permeate. There has been much diversity of opinion on 
the question of cutaneous absorption ; some maintaining that 
this membrane absorbs, while others deny it. Many experi- 
ments have proved that the skin may absorb sufficient nutri- 
ment to support life for a time, by immersing the patient in a 
bath of milk or broth. It has been found that the hand, im- 
mersed to the wrist in warm water, will absorb from ninety 
to one hundred grains of fluid in the space of an hour. 

399. Thirst may be quenched by applying moist clothes to 
the skin, or by bathing. It is no uncommon occurrence, dur- 
ing a passage from one continent to the other, for the saliva 

396. "What is recrementitial absorption ? 397. Define excrementitial 
absorption. 398. To what does cutaneous absorption relate ? Is there a 
diversity of opinion respecting this variety of absorption ? What do well 
attested experiments show ? 399. What remark in reference to quenching 
thirst ? What agency conveys medicinal substances and ointments into 
the system when rubbed on the skin ? 

16* 



186 ANATOMY, PHYSIOLOGY, AND HYGIENE. 

to become bitter by the absorption of sea water. Medicinal 
substances, such as mercury, morphine, and Spanish flies, are 
frequently introduced into the system through the skin. 

400. Respiratory absorption has reference to the lungs. 
The mucous membrane of these organs is abundantly sup- 
plied with lymphatic vessels. By their action, substances 
finely pulverized, or in the form of gas, are readily imbibed 
when inhaled into the lungs, such as metallic vapors, odorifer- 
ous particles, tobacco smoke., and other effluvia. In this way, 
contagious diseases are frequently contracted. 

Illustration. In inhaling sulphuric ether, or letheon, it is 
introduced into the vessels of the lungs in the form of vapor, 
and through them it is rapidly conveyed to the brain, and thus 
influences the nervous system. 

401. Venous absorption is the function which the veins 
perform in absorbing from the alimentary canal liquids of 
various kinds that have been taken into the stomach and are 
not converted into chyle. In other parts of the body, they 
also perform the common office of lymphatics. 

402. Lacteal, or digestive absorption has reference to the 
absorption of chyle only, which is destined for the nutrition 
of the body. 

403. Absorption is not only very abundant, but generally 
very rapid, and all these varieties are maintained through life, 
except when suspended by disease. 

400. What is said of respiratory absorption ? How is letheon introduced 
into the system ? 401. Define venous absorption. 402. What is lacteal 
absorption ? 403. What is said of absorption ? 



Fig. 85. A representation of the lymphatic vessels and glands. 1, 2, 3, 4, 5, 6, The 
lymphatic vessels and glands of the lower limbs. 7, Lymphatic glands. 8, The 
commencement of the thoracic duct. 9, The lymphatics of the kidney. 10, Of the 
stomach. 11, Of the liver. 12, 12, Of the lungs. 13, 14, 15, The lymphatics and 
glands of the arm. 16, 17, 18, Of the face and neck. 19, 20, Large veins. 21, The 
thoracic duct. 26, The lymphatics of the heart. 



PHYSIOLOGY OF THE LYMPHATIC VESSELS. 
Fiff. 85. 



187 




188 ANATOMY, PHYSIOLOGY, AND HYGIENE. 



HYGIENE OF THE LYMPHATIC VESSELS. 

404. By the action of the lymphatics, substances of an 
injurious, as well as of a beneficial, character may be con- 
veyed into the system. These vessels, under certain condi- 
tions, are more active in their office than at other periods ; 
and it is of practical utility to know what influences their 
action. 

405. The function of these vessels is increased by moisture, 
and lessened by an inactive state of the lacteals. Observation 
shows that the ill-fed, and those persons that live in marshy 
districts, contract contagious diseases more readily than those 
individuals who are well fed, and breathe a dry and pure air. 

406. The air of the sick-room should be dry. If due 
attention is not given to ventilation, the clothing of the nurse 
and. patient, together with the air of the room, will be moist- 
ened by the exhalations from the skin and lungs. This 
exhalation may contain a poison of greater or less power, 
according to its quantity and degree of concentration, and 
may be absorbed and reconveyed into the system, causing 
inflammatory diseases, and not unfrequently death. 

Observations. 1st. When we are attending a sick person, 
a current of air that has passed over the patient should be 
avoided. We may approach with safety very near a person who 
has an infectious disease, provided care is taken to keep on the 
side from which the currents of air are admitted into the room. 

2d. When we have been visiting or attending on a sick 
person, it is judicious to change the apparel worn in the 
sick-room, and also give the skin a thorough bathing. The 
outside garments, also, should be aired, as poisonous matter 
may have penetrated the meshes of the clothing. 

404 — 413. Give the hygiene of the lymphatic vessels. 404. "What is said 
respecting the action of the lymphatic vessels ? 405. What influences the 
function of these vessels ? "What does observation show ? 406. "Why- 
should the air of the sick-room be dry ? What suggestion when we have 
been visiting or attending on the sick ? 



HYGIENE OF THE LYMPHATIC VESSELS. 189 

407. The stomach should be supplied with food of a nutrient 
and digestible character, in proper quantities, and at stated 
periods. The chyle formed from the food stimulates the lac- 
teals to activity, which activity is attended with an inactive 
state of the lymphatics of the skin and lungs. Thus due 
attention should be given to the food of the attendants on the 
sick, and the members of the family. Before visiting a sick 
person it is judicious to take a moderate amount of nutritious 
food. 

Observation. Many individuals, to prevent contracting dis- 
ease that may be communicated from one person to another, 
use tobacco, either chewed or smoked ; and sometimes alcohol, 
with decoctions of bitter herbs. These substances do not 
diminish, but tend to increase, the activity of the lymphatics. 
Thus they make use of the means by which the poisonous 
matter formed in the system of the diseased person, may be 
more readily conveyed into their own. 

408. The skin and clothing, as well a§*the bed-linen, should 
be frequently cleansed. This will remove the poisonous matter 
that may be deposited upon the skin and garments, which, if 
suffered to remain, might be conveyed into the system by 
the action of the lymphatics. This points also to a frequent 
change of the wearing apparel, as well as the coverings of 
the bed. In visiting the unhealthy districts of the South and 
West, the liability of contracting disease is much lessened by 
taking a supply of food at proper periods, keeping the skin and 
clothing in a clean state, the room well ventilated, and avoid- 
ing the damp chills of evening. 

409. Absorption by the skin is most vigorous when the 
cuticle is removed by vesication, or blistering. Then exter- 

407. Why should the stomach be supplied with food of a nutrient and 
digestible character ? What is said of the use of alcohol, or tobacco, in 
preventing the introduction of the poisonous matter of contagious diseases ? 
408. Why should the clothing and bed-linen be frequently washed ? What 
suggestion to persons in visiting the unhealthy districts of the South and 
West ? 409. When is cutaneous absorption most vigorous ? Why ? 



190 ANATOMY, PHYSIOLOGY, AND HYGIENE. 

nal applications are brought into immediate contact with the 
orifices of the lymphatics of the skin, and by them rapidly 
imbibed and circulated through the system. Thus arsenic 
applied to the cutaneous vessels, and strong solutions of opium 
to extensive burns, have been absorbed in quantities sufficient 
to poison the patient. 

410. When the cuticle is only punctured or abraded, 
poisonous matter may be introduced into the system. The 
highly respected Dr. W., of Boston, lost his life by poisonous 
matter from the body of a patient subjected to a post mortem 
examination. He had removed 'from his finger, previous to 
the examination, a " hang-nail," and the poison from the 
dead body was brought in contact with the denuded part, and 
through the agency of the lymphatics it was conveyed into the 
system. 

411. Puncture any part' of the cuticle with the finest 
instrument that has upon its point the smallest conceivable 
quantity of the vaccine virus, or small-pox matter, and it will 
be brought into contact with the lymphatic vessels, and 
through their agency conveyed into the system. The result 
is, that persons thus operated upon have the small-pox, or 
the vaccine disease. 

412. When we expose ourselves to any poisonous vapors, 
or handle diseased animals or sick persons, safety and health 
require that the cuticle be not broken or otherwise injured. In 
many instances, the poisonous animal matter upon hides has 
been introduced into the systems of tanners, through small 
ulcers upon their fingers or hands. From these sores there 
would be seen small red lines extending up the arm. These 
swelled tracts indicate an inflammation of the large lymphatic 

410. Do the same results follow, if the cuticle is only punctured ? Relate 
an instance of death by the absorption of poisonous matter. 411. By 
•what means is the vaccine matter introduced into the system ? 
412. "What caution is necessary when we expose ourselves to poisonous 
vapors ? 



HYGIENE OF THE LYMPHATIC VESSELS. 191 

trunks, that have been irritated and diseased by the passage of 
poisonous matter through them into the system. 

Observation. A distressing illustration of the absorption of 
deleterious substances from the surface of a sore, is seen in 
the favorite experiments of that class of " quacks," who style 
themselves " cancer doctors.' 1 With them, every trifling and 
temporary enlargement, or tumor, is a cancer. Their gen- 
eral remedy is arsenic ; and happy is the unfortunate suf- 
ferer who escapes destruction in their hands, for too frequent- 
ly their speedy cure is death. 

413. In case of an accidental wound, it is best imme- 
diately to bathe the part thoroughly in pure water, and to 
avoid all irritating applications. In some instances, it would 
be well to apply lunar caustic immediately. When handling 
or shrouding dead bodies, or removing the skin from animals 
that have died of disease, it would be well to lubricate the 
hands with olive-oil or lard. This affords protection to the 
minute portions of the skin, from which the cuticle may 
be removed. In all cases where there is an ulcer or sore, the 
part should be covered with something impervious to fluids, 
as court-plaster, before exposing the system to any animal, 
vegetable, or mineral poison. 

413. What direction is given when the cuticle is broken ? "What sug- 
gestion is given when shrouding dead bodies ? 



192 ANATOMY, PHYSIOLOGY, AND HYGIENE. 



CHAPTER XXI. 



SECRETION 



414. In the human body are found many fluids and solids 
of dissimilar appearance and character. These are produced 
by the action of organs, some of which are of simple struc- 
ture, while others are very complicated in their arrangement. 
These organs are called Se-cre'to-ry. 

ANATOMY OF THE SECRETORY ORGANS. 

415. The secretory organs are the Ex-ha'lants, Folli- 
cles, and the Glands. 

416. The exitalants are supposed to be terminations of 
the arteries, or capillaries. The external exhalants terminate 
on surfaces that communicate with the air ; the internal, on 
surfaces not exposed to this element. 

Fife. 86. 




Fig. 86. A secretory follicle. An artery is seen, which supplies the material for its 
secretion. Follicles are also supplied with veins and organic nerves. 

417. The follicles are small bags, or sacs, situated in the 
true skin, and mucous membrane. The pores seen on the 
skin are the outlets of these bodies. 

414. How are the fluids and solids of the body produced ? 415 — 419. Give 
the anatomy of the secretory organs. 415. Name the secretory organs. 
416. Describe the exhalants. What is represented by fig. 86 ? 417. Define 
follicles. 



PHYSIOLOGY OF THE SECRETORY ORGANS. 193 

418. The glands are soft, fleshy organs, and as various in 
their structure, as the secretions which it is their function to 
produce. Each gland is composed of many small lobules 
united in a compact and distinct mass, that communicates by 
a small duct with the principal outlet, or duct of the organ. 
Every gland is supplied with arteries, veins, lymphatics, and 
nerves. These, with the ducts, are arranged in a peculiar 
manner, and connected by cellular membrane. 

419. There are two classes of glands, one for the modi- 
fication of the fluids which pass through them, as the mesenteric 
and lymphatic glands ; and the other for the secretion of fluids 
which are either useful in the animal economy, or require to 
be rejected from the body. 




Fig. 87. 1, 1, A secretory gland. 2, 2, Minute ducts that are spread through the 
glands. These coalesce to form the main duct, 3. 



PHYSIOLOGY OF THE SECRETORY ORGANS. 

420. Secretion is one of the most obscure and mys- 
terious functions of the animal economy. " It. is that process 
by which various substances are separated from the blood, 
either with or without experiencing any change during their 

418. Give the structure of the glands. 419. How are the glands arranged ? 
420 — 431. Give the physiology of the secretory organs. 420. "What is secre- 
tion ? 

17 



194 ANAT0D1Y, PHYSIOLOGY, AND HYGIENE. 

separation." Not only is the process by which substances are 
separated from the blood, called secretion, but the same term 
is also applied to substances thus separated. Thus physiolo- 
gists say, that by the process of secretion, bile is formed by 
the liver ; and also, that bile is the secretion of this organ. 

421. The secreted fluids do not exist in that form in the 
blood, but only the elements out of which they are made ; and 
the " vessels by which it is accomplished may well be called 
the architects and chemists of the system ; for out of the same 
material — the blood — they construct a variety of wonderful 
fabrics and chemical compounds. We see the same wonder- 
ful power possessed, also, by vegetables ; for out of the same 
materials the olive prepares its oil, the cocoa-nut its milk, the 
cane its sugar, the poppy its narcotic, the oak its green pulpy 
leaves, and its dense woody fibre. All are composed of the 
same few, simple elements, arranged in different order and 
proportions." 

422. " In like manner we find the vessels, in animated 
bodies, capable of forming all the various textures and sub- 
stances which compose the frame ; the cellular tissue, the 
membranes, the ligaments, the cartilages, the bones, the mar- 
row, the muscles with their tendons, the lubricating fluid of 
the joints, the pulp of the brain, the transparent jelly of the 
eye ; in short, all the textures of the various organs of which 
the body is composed, consist of similar ultimate elements, 
and are manufactured from the blood." 

423. Of the agents that produce or direct the different 
secretions, we have no very accurate knowledge. Some have 
supposed this function to be mechanical, others a chemical 
process, but experiments prove that it is dependent on nervous 
influence. If the nerves are divided which are distributed to 



421. What is said respecting secreted substances ? Do vegetables possess 
the property of secretion ? 422. From what are the various textures 
formed ? 423. Have we accurate knowledge of the agents that produce 
secretion ? 



PHYSIOLOGY OF THE SECRETORY ORGANS. 195 

any organ, the process of secretion is suspended. It is no 
uncommon occurrence, that the nature of milk will be so 
changed from the influence of anger in the mother, as to cause 
vomiting, colic, and even convulsions, in the infant that swal- 
lows it. Unexpected intelligence either of a pleasant or 
unpleasant character, by its influence on the nervous system, 
will frequently destroy the appetite. Sometimes mental agita- 
tion, as fear, will cause a cold sweat to pervade the surface 
of the body. 

424. Secretions are constantly maintained, during life, from 
the serous membrane, by the action of the internal exhalants. 
The fluid which is exhaled bears some resemblance to the 
serum of the blood. Its use is to furnish the organs, which 
are surrounded by this membrane, with a proper degree of 
moisture, and thus enables them to move easily on each other, 
as those within the chest and abdomen. 

425. The cellular tissue exhales a serous fluid, and when 
it becomes excessive in quantity, general dropsy is produced. 
Fat is another secretion, which is thrown out, in a fluid state, 
from the cellular membrane. It is deposited in little cells, 
and exists in the greatest abundance between the skin and the 
muscles. Its use seems to be, to form a cushion around the 
body for its protection ; to furnish nutriment for the system 
when food cannot be taken ; to supply the carbon and hydro- 
gen necessary to sustain the generation of heat, when these 
articles of combustion are not otherwise furnished. The 
med ul-la-ry substance, (marrow,) in the cavities of the long 
bones, is very much like fat. 

Observation. During sickness, if there is not emaciation 
or absorption of this secretion, it is considered an unfavorable 
symptom, because it indicates a want of power in the absorb- 
ing system, which is among the last to be affected. 

How is it proved that secretion depends on nervous influence ? 424. "What 
is said of the secretions from the serous membrane ? 425. From what tissue 
is a serous fluid exhaled ? "What is the effect when this fluid becomes 
excessive in quantity ? Vvhat is fat ? Its use ? What is marrow ? 



196 



ANATOMY, PHYSIOLOGY, AND HYGIENE. 



426. The mucous secretion is a transparent, viscid fluid, 
which is secreted by those membranes that line the cavities 
of the body, which have an external communication, as the 
trachea and alimentary canal. This secretion serves to pro- 
tect these parts from the influence of the air, and concurs, by 
means of its peculiar properties, in the performance of their 
functions. 

427. There are two external secretions, namely, one from 
the skin, called perspiration, and the other from the lungs. 
The cutaneous exhalation, or transpiration * exists in two 
forms, called sensible perspiration (sweat) and insensible per- 
spiration. The pulmonary exhalation is the most important 
and universal, and closely resembles that of the skin. 

428. The follicles are found only in the skin and mucous 
membrane. They secrete an oily, unctuous substance, which 
mixes with the transpiration, and lubricates the skin. At the 
root of each hair there is a minute follicle, which secretes the 
fluid that oils the hair. The wax in the passage of the ear is 
secreted from these bodies. 

429. All the blood distributed to the different glands is 
similar in composition and character ; but the fluids secreted 
by them, vary in appearance in a remarkable degree. The 
ofTice of the glands appears to be principally to form different 
secretions. Thus the salivary glands secrete the insipid 
saliva; the lachrymal glands, the saline tears; the liver, the 
yellow, ropy bile ; and the kidneys, the acrid urine. 

430. Some secretions are evidently produced only in par- 



* Transpiration is a term often used generically, to signify trie pas- 
sage of fluids or gases through, membranes, internally or externally ; 
but perspiration is a specific term, signifying transpiration on to the 
external surface. 

426. "What is said relative to the mucous secretion ? 427. Name the 
external secretions. 428. Give the office of the follicles. 429. What 
appears to be the principal office of the glands ? 430. Mention a secretion 
produced in a particular emergency. 



HYGIENE OF THE SECRETORY ORGANS. 197 

ticular emergencies, as is seen in the increased secretion of 
bony matter when a limb is broken. 

431. When any substance which is not demanded for 
nutrition, or does not give nourishment to the system, is 
imbibed by the lymphatic vessels, and conveyed into the blood, 
it is eliminated in the secretions. 

Illustration. A few years since, a poor inebriate was 
carried to a London hospital in a state of intoxication. He 
lived but a few hours. On examining his bram, nearly half a 
gill of fluid, strongly impregnated with gin, was found in the 
cavities of this organ. This was secreted from the vessels of 
the brain. 



HYGIENE OF THE SECRETORY ORGANS. 

432. Unless the secretions are regularly maintained, disease 
will he the ultimate result. Let the secretions from the skin 
be suppressed, and fever or some internal inflammation will 
follow. If the bile is impeded, digestion will be impaired. 
If any other secretion is suppressed, it will cause a derange- 
ment of the various internal organs. 

Observation. Ardent spirits derange the secretions, and 
change the structure of the brain. This is one reason why 
inebriates do not generally live to advanced age. 

433. The quantity of blood influences the character of the 
secretions. If it is lessened to any great extent, the secre- 
tions will be lessened as well as changed in character. 

Illustration. When a person has lost a considerable 
quantity of blood, there is a sensation of thirst in the fauces, 
attended with a cold, pale, dry skin. When reaction comes 

431. "What becomes of those substances imbibed by the lymphatics that 
do not give nourishment to the body. 432 — 437. Give the hygiene of the 
secretory organs. 432. "What effect on the system when the secretions 
are not regularly maintained ? 433. Does the quantity of blood influence 
the secretions ? Give an illustration. 

17* 



198 ANATOMY, PHYSIOLOGY, AND HYGIENE. 

on, the perspiration is cold, attended with nausea, and some- 
times vomiting. 

434. The secretory organs require the stimulus of pure 
Mood. If this fluid is vitiated, the action of the secretory 
organs will be more or less modified. Either the quantity 
will be affected or the quality will be altered. 

Observation. The impurity of the blood arising from the 
inhalation of the vitiated air of sleeping rooms, diminishes 
and changes the character of the secretions of the mouth and 
stomach. This accounts for the thirst, coated tongue, and 
disagreeable taste of the mouth when impure air is breathed 
during sleep. The disease it induces, is indigestion or dys- 
pepsia. 

435. The amount of action modifies the condition of the 
secretory organs. When a secretory organ is excessively 
stimulated, its vigor and energy are reduced. The subse- 
quent debility may be so great as to suppress or destroy its 
functional power. 

Illustrations. 1st. In those sections of the country where 
flax is spun on a " foot-wheel," it is not unfrequent that the 
spinners moisten the thread with the secretions of the mouth. 
This seems to operate economically for a time, but debility of 
the salivary organs soon follows, which incapacitates them 
from supplying saliva sufficient to moisten the food, producing 
in a short time disease of the digestive organs. 

2d. The habit of continual spitting, which attends the 
chewing of tobacco and gums, and other substances, between 
meals, induces debility, not only of the salivary glands, but 
of the system generally. 

436. One secretory organ may do the office of another. 
This increased action of a secretory organ may be sustained 

434. What is the effect of impure blood on the secretory organs ? 
435. What results from stimulating excessively a secretory organ ? How 
is this illustrated ? 436. What is the effect when one secretory organ per- 
forms the office of another ? 



HYGIENE OF THE SECRETORY ORGANS. 199 

for a limited time without permanent injury, but, if long con- 
tinued, a diseased action of the organ will follow. Of mor- 
bid secretions we have examples in the ossification of the 
valves of the heart, cancerous and other tumors. 

Observatioji. In the evenings of the warm season, a chill 
upon the impressible skin, that suppresses the perspiration, is 
frequently followed by a diarrhoea, dysentery, or cholera 
morbus. These can be prevented by avoiding the chill. An 
efficient means of relief, is immediately to restore the skin to 
its proper action. 

437. The secretions are much influenced by the mind. How 
this is effected, it is difficult to explain ; but many facts corrob- 
orate it. Every one has felt an increased action of the tear- 
glands from distressing feelings. Cheerfulness of disposition 
and serenity of the passions are peculiarly favorable to the 
proper performance of the secretory function. From this we 
may learn how important it is to avoid such things as distract, 
agitate, or harass us. 

Observation. In fevers and other diseases, when the skin, 
mouth, and throat are dry from a suppression of the secretions, 
let the mind of the patient be changed from despondency to 
hope, and the skin and the membrane that lines the mouth and 
throat will exhibit a more moist condition, together with a 
general improvement of the vital organs of the system. 
Consequently, all just encouragement of the restoration to 
health should be given to a sick person. 

Give examples of morbid secretions. What is one cause of dysentery 
and cholera morbus? How can these affections be relieved ? 437. Show 
the influence of the mind on the secretions. Mention instances of its 
influence. 



200 ANATOMY, PHYSIOLOGY, AND HYGIENE. 



CHAPTER XXII. 

NUTRITION. 

438. Nutrition is the vital act by which the different 
parts of the body renew the materials of which they are 
composed. Digestion, circulation, absorption, and respi- 
ration, are but separate links in the chain of nutrition, 
which would be destroyed by the absence of any one of 
them. 

439. The nutritive process is also a kind of secretion, by 
which particles of matter are separated from the blood and 
conveyed with wonderful accuracy to the appropriate tex- 
tures. The function of the nutrient vessels antagonizes those 
of absorption : while one system is constructing, with beautiful 
precision, the animal frame, the other is diligently employed 
ill pulling down this complicated structure. 

440. This ever-changing state of the body is shown by 
giving animals colored matter, mixed with their food, which 
in a short time tinges their bones with the same color as 
the matter introduced. Let it be withdrawn, and in a few 
days the bones will assume their former color — evidently 
from the effects of absorption. The changeful state of the 
body is further shown by the losses to which it is subjected ; 
by the necessity of aliment ; by the emaciation which follows 
abstinence from food. 



438 — 454. What remarks respecting nutrition ? 438. What is nutrition ? 
439. "What is said of the nutritive process ? The function of the nutrient 
vessels ? 440. Give a proof of the ever-changing state of the body. Give 
other instances illustrative of the changeful state of the body. 



NUTRITION. 201 

441. Every part of the body is subject to this continual 
change of material, yet it is effected with such regularity, 
that the size, shape, and appearance, of every organ is pre- 
served ; and after an interval of a few years, there may not 
remain a particle of matter which existed in the system at a 
former period. Notwithstanding this entire change, the per- 
sonal identity is never lost. 

442. Many calculations have been made to determine in' 
what length of time the whole body is renewed. Some have 
supposed that it is accomplished in four years ; others have 
fixed the period at seven years ; but the time of the change is 
not definite, as was supposed by a genuine son of the Emerald 
Isle, who had been in America seven years and three months, 
and consequently maintained that he was a native American. 

Observation. India ink, when introduced into the skin, is 
not removed ; hence some assert that this tissue is an excep- 
tion to the alternate deposition and removal of its atoms. 
The ink remains because its particles are too large to be 
absorbed, and when in the skin it is insoluble. 

443. " Those animals which are most complicated in their 
structure, and are distinguished by the greatest variety of 
vital manifestations, are subject to the most rapid changes of 
matter. Such animals require more frequent and more 
abundant supplies of food ; and, in proportion as they are 
exposed to the greater number of external impressions, will 
be the rapidity of this change of matter." 

444. " Animals may be situated so that they lose nothing 
by secretion ; consequently, they will require no nutriment. 
Frogs have been taken from fissures in solid lime rock, which 

441. "Why is the personal identity never lost in the change of materials, 
which is unceasing in the system ? 442. Give the opinion of physiologists 
respecting the time required for the renewal of the whole body. What 
exception to the changing state of the different textures ? 443. What 
animals are subject to the most rapid changes of material? 444. May 
animals be situated so that they require no nutriment ? W T hat is related 
of frogs ? 



202 ANATOMY, PHYSIOLOGY, AND HYGIENE. 

were imbedded many feet below the surface of the earth, and, 
on being exposed to the air, exhibited signs of life." 

445. The renovation of the bone, muscle, ligament, ten- 
don, cartilage, fat, nerve, hair, &c, is not perfected merely 
by the general circulation of the fluid which is expelled from 
the left side of the heart, but through the agency of a system 
of minute vessels, which, under ordinary circumstances, can- 
not be seen by the eye, even when aided by the microscope ; 
still, minute as they are, the function of these agents is neces- 
sary to the continuance of life. They are the smallest capil- 
lary vessels, and are called the nutrient arteries. 

446. " As the blood goes the round of the circulation, the 
nutrient capillary vessels select and secrete those parts which 
are similar to the nature of the structure, and the other por- 
tions pass on ; so that every tissue imbibes and converts to its 
own use the very principles which it requires for its growth ; 
or, in other words, as the vital current approaches each organ, 
the particles appropriate to it feel its attractive force, — obey 
it, — quit the stream, — mingle with the substance of its 
tissue, — and are changed into its own true and proper 
nature." 

447. Thus, if a bone is broken, a muscle or a nerve 
wounded, and, if the system is in a proper state of health, 
the vital economy immediately sets about healing the rupture. 
The blood, which flows from the wounded vessels, coagulates 
in the incision, for the double purpose of stanching the wound, 
and of forming a matrix for the regeneration of the parts. 
Very soon, minute vessels shoot out from the living parts into 
the coagulum of the blood, and immediately commence their 
operations, and deposit bony matter, where it is required 
to unite fractured bones, and nervous substance to heal the 
wounded nerve, &c. 

445. Show how the renovation of the bones, muscles, &c., is perfected. 
446. What is said of the office of the nutrient capillary vessels ? 447. When 
a bone is fractured, by what process is it healed ? 



NUTRITION. 203 

448. But the vital economy seems not to possess the power 
of reproducing the muscles and true skin, and therefore, 
when these parts are wounded, the rupture is repaired by a 
gelatinous substance, which gradually becomes hard, and 
sometimes assumes something of a fibrous appearance. It so 
perfectly unites the divided muscle, however, as to restore its 
functional power. Whea the cuticle is removed, it is repro- 
duced and no scar remains ; but, when the true skin is de- 
stroyed, a scar is formed. 

449. It is not uncommon that the nutrient arteries have 
their action so much increased in some parts, as to produce 
preternatural growth. Sometimes the vessels whose function 
it is to deposit fat, are increased in action, and wens of no 
inferior size are formed. Again, there may be a deposition 
of substances unlike any known to exist in the body. Occa- 
sionally, these nutrient arteries of a part take on a new action, 
and not only deposit their ordinary substance, but others, 
which they have not heretofore secreted, but which are formed 
by vessels of other parts of the body. It is in this way that 
we account for the bony matter deposited in the valves of the 
heart and brain, also the chalky deposits around the finger- 
joints. 

450. In infancy and childhood, the function of nutrition is 
very active ; a large amount of food is taken, to supply the 
place of what is lost by the action of the absorbents, and also 
to contribute to the growth of the body. In middle age, nutri- 
tion and absorption are more equal ; but in old age, the ab- 
sorbents are more active than the nutrient vessels. The size, 
consequently, diminishes, the parts become weaker, the bones 
more brittle, the body bends forward, and every function 
exhibits marks of decay and dissolution. 

451. A striking instance of active absorption in middle 

448- What occurs when a muscle is divided ? 449. State some of the 
results of an increased action of the nutrient arteries. 450. When is nu- 
trition most active ? How in middle age ? How in old age ? 451. Relate 
a striking instance of active absorption in middle age. 



204 



ANATOMY, PHYSIOLOGY, AND HYGIENE. 



age was exhibited in the person of Calvin Edson, of Ver- 
mont, who was exhibited in the large towns of New England, 
as the " living skeleton." In early manhood he was athletic, 
and weighed one huridred and sixty pounds ; but the exces- 
sive action of the absorbents over the nutrient vessels, re- 
duced his weight, in the interval of eighteen years, to sixty 
pounds. 

452. Instances, on the other hand, have occurred, of the 
action of the nutrient vessels exceeding, in an extreme de- 
gree, those of absorption ; as in the person of a colored girl, 
thirteen years of age, who was exhibited in New York in the 
summer of 1840. She was of the height of misses at that 
age, but weighed five hundred pounds. Several cases are on 
record of persons weighing eight hundred pounds. 

453. As already mentioned, the blood is the nutritive fluid 
of animals. When this fluid is coagulated, a thick, jelly-like 
mass floats in the serum, called fibrin. On the under sur- 
face of the mass of fibrin adheres red globulated matter. 
The color of the red globules is owing to the presence of 
iron, though some physiologists think it depends on an animal 
substance of a gelatinous character. 

Observation. That portion of the serum which remains 
fluid after coagulation by heat has taken place, is called 
se-ros'i-ty. It is more abundant in the blood of old, than in 
that of young animals ; and it forms the " red gravy " in 
roasted meats. 

454. The blood is not necessarily red. It may be white, 
as in the fish ; transparent, as in the insect ; or yellowish, as in 
the reptile. There is no animal in which the blood is red in 
all parts of the body. The ligaments and tendons in man 
are not supplied with red, but with white blood. 

452. Of excessive nutrition in early life. 453. Describe the parts that 
enter into the composition of the blood. What part of the blood forms 
the red gravy in roasted meats ? 454. Is the blood necessarily red ? Of 
•what color is the blood of the fish ? The insect ? The reptile ? What 
part of the human system has white blood ? 



HYGIENE OF NUTRITION. 205 



HYGIENE OF NUTRITION. 

455. Healthy nutrition requires pure Mood. If the nutrient 
arteries of the bones are supplied with impure blood, they 
will become soft and brittle, their vitality will be impaired, and 
disease will be the ultimate result. The five hundred mus- 
cles receive another portion of the blood. These organs are 
attached to, and act upon the bones. Upon the health and 
contractile energy of the muscles depends the ability to labor. 
Give these organs of motion impure blood, which is an 
unhealthy stimulus, and they will become enfeebled, the step 
will lose its elasticity, the movement of the arm will be 
inefficient, and every muscle will be incapacitated to perform 
its usual amount of labor. 

456. When the stomach, liver, and other organs sub- 
servient to the digestion of food, are supplied with impure 
blood, the digestive process is impaired, causing faintness and 
loss of appetite, also a deranged state of the intestines, and, 
in general, all the symptoms of dyspepsia. 

457. The delicate structure of the lungs, in which the 
blood is or should be purified, needs the requisite amount of 
pure blood to give them vigor and health. When the blood is 
not of this character, the lungs themselves lose their tone, and, 
even if permitted to expand freely, have not power fully to 
change the impure quality of this circulating fluid. 

458. The health and beauty of the skin require that the 
blood should be well purified ; but, if the arteries of the skin 
receive vitiated blood, pimples and blotches appear, and the 
individual suffers from " humors.'" Drinks, made of various 



455 — 462. Give the hygiene of nutrition. 455. What is the effect of 
impure blood upon the bones ? On the muscles ? 458. On the digestive 
organs ? 457. On the lungs ? 458. What is the effect if the vessels of the 
skin are supplied with vitiated blood ? 

18 



206 ANATOMY, PHYSIOLOGY, AND HYGIENE. 

kinds of herbs, as well as pills and powders, are taken for 
this affection. These will never have the desired effect, 
while the causes of impure blood exist. 

459. If the nutrient arteries convey impure material to the 
brain, the nervous and bilious headache, confusion of ideas, 
loss of memory, impaired intellect, dimness of vision, and 
dulness of hearing, will be experienced ; and in process of 
time, the brain becomes disorganized, and the brittle thread 
of life is broken. 

Observations. 1st. An exertion of any organ beyond its 
powers, induces weakness that will disturb the nutrition of the 
part that is called into action ; and it recovers its energy 
more slowly in proportion to the excess of the exertion. The 
function of the organ may be totally and permanently de- 
stroyed, if the exertion is extremely violent. We sometimes 
see palsy produced in a muscle simply by the effort to raise 
too great a weight. The sight is impaired, and total blind- 
ness may be produced, by exposure to light too strong or too 
constant. The mind may be deranged, or idiocy may follow 
the excess of study or the over-tasking of the brain. 

2d. When the function of an organ is permanently impaired 
or destroyed by over-exertion, the nutrition of the part is 
rendered insufficient, or is entirely arrested ; and then the 
absorbents remove it wholly or partially, as they do every 
thing that is no longer useful. Thus, in palsied patients, a 
few years after the attack, we often find scarce any trace of 
the palsied muscles remaining ; they are reduced almost to 
simple cellular tissue. The condition of the calf of the leg, 
in a person having a club-foot, is a familiar proof of this. 

460. The blood may be made impure, by the chyle being 
deficient in quantity or defective in quality. This state of 



459. How does impure blood affect the brain ? What is the eft'ect when 
any organ is exerted beyond its powers ? "What is the effect when an 
organ is permanently impaired ? 460. How may the blood become impure ? 



HYGIENE OF NUTRITION. 207 

the chyle may be produced by the food being improper in 
quantity or quality, or by its being taken in an improper 
manner, at an improper time, and when the system is not 
prepared for it. The remedy for impure blood produced in 
any of these ways is to correct the injudicious method of 
using food. (See Chapters XV. and XVI.) 

461. The blood may also be rendered impure, by not sup- 
plying it with oxygen in the lungs, and by the carbon not 
being eliminated from the system through this channel. The 
remedy for " impurities of the blood," produced in this man- 
ner, would be, to carefully reduce to practice the directions in 
the chapters on the hygiene of the respiratory organs, rela- 
tive to the free movements of the ribs and diaphragm, and 
the proper ventilation of rooms. 

462. A retention of the waste products of the skin produces 
impure blood. When the vessels of the skin, by which the 
waste, useless material is eliminated from the system, have 
become inactive by improper and inadequate clothing, or by 
a want of cleanliness, the dead, injurious atoms of matter 
are retained in the circulatory vessels. The only suc- 
cessful method of purifying the blood and restoring health 
when this condition exists, is to observe the directions given 
relative to clothing and bathing. (See Chapters XXXIII. 
and XXXIV.) 

Observation. If the blood has become " impure," or 
" loaded with humors," (an idea generally prevalent,) it is 
not and cannot be " purified " by taking patent pills, powders, 
drops, &c. But, on the contrary, by observing the suggestions 
in the preceding paragraphs, the blood can be freed of its 
impurities, and, what is of greater importance, such " injurious 
humors " will be prevented. 

461. Mention another means by which the blood may be made impure. 
How remedied. ? 462. What is the effect of want of cleanliness upon the 
blood ? "What is said respecting " humors " in the blood ? 



208 



ANATOMY, PHYSIOLOGY, AND HYGIENE. 

Fig-. 88. 

m Ill.!24 




Fig. 88. A front view of the organs within the chest and abdomen. 1, 1, 1, 1, The 
muscles of the chest, a, 2, 2, 2, The ribs. 3,3,3, The upper, middle, and lower 
lobes of the right lung. 4, 4, The lobes of the left lung. 5, The right ventricle of 
the heart. 6, The left ventricle. 7, The right auricle of the heart. 8, The left auri- 
cle. 9, The pulmonary artery. 10, The aorta. 11, The vena cava descefidens. 
12, The trachea. 13, The oesophagus. 14, 14,14, 14, The pleura. 15, 15, 15, The 
diaphragm. 16, 16, The right and left lobe of the liver. 17, The gall-cyst. 18, The 
stomach. 25, The spleen. 19, 19, The duodenum. 20, The ascending colon 
21, The transverse colon. 25, The descending colon. 22, 22, 22, 22, The small 
intestine. 23, 23, The abdominal walls turned down. 24, The thoracic duct, opening 
into the left subclavian vein, (27.) 



ANATOMY OF THE RESPIRATORY ORGANS. 209 



CHAPTER XXIII. 

THE RESPIRATORY ORGANS. 

463. The nutrient portion of the food is poured into the 
left subclavian vein, (24, 27, fig. 88,) at the lower part of the 
neck, and is carried to the right cavities of the heart. The 
fluid in these cavities consists of the chyle incorporated with 
the venous blood. Neither of these two elements is fitted to 
promote the growth or repair the waste of the body. They 
must be subjected to a process, by which the first can be 
converted into blood, and the second freed of its carbonic 
acid gas and water. This is effected by the Respiratory 
Organs. 

ANATOMY OF THE RESPIRATORY ORGANS. 

464. The respiratory organs are the Lungs, (lights,) 
the Tra'clie-a, (windpipe,) the Bronclii-a, (subdivisions of the 
trachea,) and the Air- Ves'i-cles, (air-cells at the extremities of 
the bronchia.) The Di'a-phragm, (midriff,) Ribs, and several 
Muscles, also aid in the respiratory process. 

465. The lungs are conical organs, one on each side of 
the chest, embracing the heart, (fig. 88,) and separated from 
each other by a membranous partition. The color of the 
lungs is a pinkish gray, mottled, and variously marked with 
black. Each lung is divided into lobes, by a long and deep 

463. What fluids are conveyed into the right cavities of the heart ? 
"What is necessary before they can be adapted to the -wants of the body ? 
By what organs are these changes effected ? 464 — 474. Give the anatomy 
of the respiratory organs. 464. Name the respiratory organs. What organs 
also aid in the respiratory process ? 465. Describe the lungs. 

18* 



210 



ANATOMY, PHYSIOLOGY, AND HYGIENE. 



fissure, which extends from the posterior surface of the upper 
part of the organ, downward and forward, nearly to the 
anterior angle of the base. In the right lung, the upper lobe 
is subdivided by a second fissure. This lung is larger and 
shorter than the left. It has three lobes, while the left has 
only two. 

Fiff. 89. 




'Is 

Fig. 89. A back view of the heart and lungs. The posterior walls of the chest are 
removed. 1, 2, 3, The upper, middle, and lower lobes of the right lung. 8, 9, 10, The 
two lobes of the left lung. 6, 13, The diaphragm. 7,7, 14, 14, The pleura that lines 
the ribs. 4,11, The pleura that lines the mediastine. 5,12,12, The portion of the 
pleura that covers the diaphragm. 15, The trachea, 16, The larynx. 19, 19, The 
right and left bronchia. 20, The heart. 29, The lower part of the spinal column. 



Explain fig. 89. 



ANATOMY OF THE RESPIRATORY ORGANS. 



211 



466. Each lung is enclosed, and its structure maintained, 
by a serous membrane, called the pleu'ra, which invests it as 
far as the root, and is thence reflected upon the walls of the 
chest. The lungs, however, are on the outside of the pleura, 
in the same way as the head is on the outside of a cap doubled 
upon itself. The reflected pleurae in the middle of the thorax 
form a partition, which divides the chest into two cavities. 
This partition is called the me- di- as 1 line. 

Fig. 90. 




Fig. 90. The heart and lungs removed from the chest, and the lungs freed from 
all other attachments. 1, The right auricle of the heart. 2, The superior vena 
cava. 3, The inferior vena cava. 4, The right ventricle. 5, The pulmonary artery 
issuing from it. a, a, The pulmonary artery, (right and left,) entering the lungs. 
b, b, Bronchia, or air-tubes, entering the lungs, v, v, Pulmonary veins, issuing from 
the lungs. 6, The left auricle. 7, The left ventricle. 8, The aorta. 9, The upper 
lobe of the left long. 10, Its lower lobe. 11, The upper lobe of the right lung. 
12, The middle lobe. 13, The lower lobe. 

Observation. When this membrane that covers the lungs, 



466. By what are the lungs enclosed ? What is the relative position of 
the lungs and pleura ? What is said of the reflected pleurae ? Explain 
fig. 90. What part of the lungs is affected in pleurisy ? 



212 ANATOMY, PHYSIOLOGY, AND HYGIENE. 

and also lines the chest, is inflamed, the disease is called 
" pleurisy." 

467. The lungs are composed of the ramifications of the 
bronchial tubes, which terminate in the bronchial cells, (air- 
cells,) lymphatics, and the divisions of the pulmonary artery 
and veins. All of these are connected by cellular tissue, 
which constitutes the pa-ren'chy-ma. Each lung is retained 
in its place by its root, which is formed by the pulmonary 
arteries, pulmonary veins, and bronchial tubes, together with 
the bronchial vessels and pulmonary nerves. 

468. The trachea extends from the larynx, of which it is a 
continuation, to the third dorsal vertebra, where it divides into 
two parts, called bronchia. It lies immediately anterior to 
the spinal column, from which it is separated by the oesoph- 
agus. 

469. The bronchia proceed from the bifurcation, or di- 
vision of the trachea, to their corresponding lungs. Upon 
entering the lungs, they divide into two branches, and each 
branch divides and subdivides, and ultimately terminates in 
small sacs, or cells, of various sizes, from the twentieth to 
the hundredth of an inch in diameter. So numerous are these 
bronchial or air-cells, that the aggregate extent of their lining 
membrane in man has been computed to exceed a surface of 
20,000 square inches, and Munro states that it is thirty times 
the surface of the human body. 

Illustration. The trachea may be compared to the trunk of 
a tree ; the bronchia, to two large branches ; the subdivisions 
of the bronchia, to the branchlets and twigs ; the air-cells, to 
the buds seen on the twigs in the spring. 

470. The air-vesicles and small bronchial tubes compose 

s 467. Of what are the lungs composed ? How retained, in place ? 
468. Where is the trachea situated ? 469. Describe the bronchia. "What 
is the aggregate extent of the lining membrane of the air-cells ? To what 
may the trachea and its branches be compared ? 470. What is said of 
the air-cells and bronchial tubes ? 



ANATOMY OF THE RESPIRATORY ORGANS. 



213 



the largest portions of the kings. These, when once inflated, 
contain air, under all circumstances, which renders their spe- 
cific gravity much less than water ; hence the vulgar term, 
lights, for these organs. The trachea, bronchia, and air-cells 
are lined* by mucous membrane. The structure of this mem- 
brane is such, that it will bear the presence of pure air without 
detriment, but not of other substances. 

Fie. 91. 




Fig. 91. A representation of the larynx, trachea, bronchia, and air-cells. 1, 1, 1, 
An outline of the right lung. 2, 2, 2, An outline of the left lung. 3, The larynx. 
4, The trachea. 5, The right bronchial tube. 6, The left bronchial tube. 7, 7, 7, 
8, 8,8, The subdivisions of the right and left bronchial tubes. 9, 9, 9, 9, 9, 9, Air- 
cells. 



"What membrane lines the trachea and its branches ? "What is peculiar 
in its structure ? "What does fig. 91 represent ? 



214 



ANATOMY, PHYSIOLOGY, AND HYGIENE. 



Observation. The structure of the trachea and lungs may 
be illustrated, by taking these parts of a calf or sheep and 
inflating the air-vesicles by forcing air into the windpipe with 
a pipe or quill. The internal structure may then be seen 
by opening the different parts. 

471. The lungs, like other portions of the system, are sup- 
plied with nutrient arteries and nerves. The nervous filaments 
that are distributed to these organs are in part from the tenth 
pair, (par vagum,) that originates in the brain, and in part from 
the sympathetic nerve. The muscles that elevate the ribs and 
the diaphragm receive nervous fibres from a separate system, 
which is called the respiratory. 

Fig. 92. 




Fig. 92. 1, A bronchial tube. 2, 2, 2, Air-vesicles. Both the tube and vesicles 
are much magnified. 3, A bronchial tube and vesicles laid open. 

Observation. When the mucous membrane of a few of the 
larger branches of the windpipe is slightly inflamed, it is called 
a " cold ;" when the inflammation is greater, and extends to the 
lesser air-tubes, it is called bronch-i'tis. When the air-cells 
and parenchyma become inflamed, it is called inflammation 
of the lungs. Coughing is a violent expulsory effort by which 
air is suddenly forced through the bronchia and trachea to 
remove offending matter. 



How may the structure of the trachea and its branches be illustrated ? 
471. Are the lungs supplied with nutrient arteries ? Where are the 
respiratory nerves distributed ? From what so\irce do these organs derive 
their nervous filaments ? 



ANATOMY OF THE RESPIRATORY ORGANS. 215 

472. The ribs are joined to the spinal column at their 
posterior extremity ; and in front, they terminate in cartilages, 
which unite them to the sternum. They incline downward, 
from the spinal column to the breast-bone. 



Fig. 93. 




Fig. 93. A section of the chest when the lungs are inflated. 1, The diaphragm. 
2, The muscular walls of the abdomen. 

Fig. 94. A section of the chest when the lungs are contracted. 1, The diaphragm, 
in common expiration. 2, 2, The muscular walls of the abdomen. 3, The position 
of the diaphragm in forced expiration. 

These engravings show the diaphragm to be more convex, and the walls of the 
abdomen more flattened, when the lungs are collapsed, than when they are inflated. 

473. The diaphragm is a flexible circular partition, that 
separates the respiratory from the digestive organs, and the 
chest from the abdomen. Its margin is attached to the spinal 
column, the sternum, and cartilages of the lower ribs. The 
lungs rest upon its upper surface, while the liver and stomach 

472. Describe the ribs. Explain figs. 93 and 94. 473. Describe the dia- 
phragm. 



216 ANATOMY, PHYSIOLOGY, AND HYGIENE. 

are placed below it, (fig. 88.) In a state of repose, its upper 
surface forms an arch, the convexity of which is toward the 
chest. In forced expiration, its upper point reaches as high 
as the fourth rib. In an ordinary inspiration, it is depressed 
as low as the seventh rib, which increases the capacity of the 
chest. 

474. The respiratory muscles are, in general, attached 
at one extremity to the parts about the shoulders, head, and 
upper portion of the spinal column. From these, they run 
downward and forward, and are attached, at the opposite 
extremity, to the sternum, clavicle, and upper rib. Other 
muscles are attached at one extremity to a rib above, and by 
the opposite extremity to a rib below. These fill the spaces 
between the ribs, and, from their situation, are called in-ter- 
cost'al muscles. 

Observation. 1st. There are several actions of common 
occurrence, that are intimately connected with respiration ; 
such as hiccough, sneezing, &c. Hiccough is an involuntary 
contraction of the muscles of respiration, particularly the dia- 
phragm. 

2d. Sneezing is a violent, involuntary contraction of the 
respiratory muscles, as in hiccough. When an acrid stimu- 
lant, as snuff, is applied to the mucous membrane of the nose, 
an irritation is produced which is accompanied by a violent 
expulsion of air from the lungs. This is owing to the con- 
nection between the nasal and respiratory nerves. 

What is its form when not in action ? 474. Where do the respiratory 
muscles make their attachment ? What name is given to those muscles 
that fill the places between the ribs ? What is hiccough ? What is 
sneezing ? 



PHYSIOLOGY OF THE RESPIRATORY ORGANS. 217 



CHAPTER XXIV. 

PHYSIOLOGY OF THE RESPIRATORY ORGANS. 

475. Respiration, or breathing, is that process by which air 
is taken into the lungs and expelled from them. The object of 
respiration is, 1st. To supply the system with oxygen, which is 
essential to the generation of animal heat ; 2d. To convert the 
chyle into blood. This is done by the oxygen of the inspired 
air ; 3d. To relieve the organs of the body of the principal 
elements (carbon and hydrogen) that compose the old and 
useless particles of matter. The organs of the system, as 
already mentioned, are principally composed of carbon, hy- 
drogen, oxygen, and nitrogen. 

476. By the action of the lymphatics and capillary veins, 
the old and worn-out particles are conveyed into the veins of 
the systemic circulation. The hydrogen, in form of watery 
vapor, is easily discharged in the perspiration and other secre- 
tions. The nitrogen and oxygen are, or may be, separated 
from the blood, without the necessity of any particular organ ; 
but carbon does not escape so readily. It is probable that a 
part of the surplus carbon of the venous blood is secreted by 
the liver ; but a far greater amount passes to the lungs, and 
these may be considered as special organs designed to sepa- 
rate this element from the venous blood. 

477. An ordinary inspiration may be accomplished by the 
action of the diaphragm, and a slight elevation of the ribs. In 

475 — 494. Give the physiology of the respiratory organs. 475. What is 
respiration ? "What is the principal object in breathing ? 476. How are 
the useless atoms of matter conveyed into the veins of the systemic circu- 
lation ? How may the principal elementary substances be separated from 
the blood ? 477- How may an ordinary inspiration be accomplished ? 

19 



218 



ANATOMY, PHYSIOLOGY, AND HYGIENE. 



full inspiration, the diaphragm is not only more depressed, 
but the ribs are evidently elevated. To produce this effect on 
the ribs, two sets of muscles are called into action. Those 
which are attached to the upper rib, sternum, and cavicle, 
contract and elevate the lower and free extremities of the ribs. 
This enlarges the cavity of the chest between the spinal 
column and the sternum. But the lateral diameter, in conse- 
quence, is only slightly increased, because the central portion 
of the ribs sinks lower than their posterior extremities, or 
their cartilaginous attachment to the sternum. 

Fig. 95. 




Fig. 95. 6, Four of the vertebra, to which are attached three ribs, (7, 7,7,) with 
their intercostal muscles, (8, 8.) These ribs, in their natural position, have their 
anterior cartilaginous extremity at 4, while the posterior extremity is attached to the 
vertebrae, (6,) which are neither elevated nor depressed in respiration. 1, 1, and 
2, 2, parallel lines, within which the ribs lie in their natural position. If the anterior 
extremity of the ribs is elevated from 4 to 5, they will not lie within the line 2, 2, but 
will reach the line 3, 3. If two bands extend from 1, 1, to 2, 2, they will effectually 
prevent the elevation of the ribs from 4 to 5, as the line 2, 2, cannot be moved to 3, 3. 

478. The central portion of the ribs is raised by the action 
of intercostal muscles. The first, or upper rib, has but little 
movement ; the second has more motion than the first, while 



"What effect has a full inspiration on the ribs and diaphragm ? How is 
the chest enlarged between the spinal column and sternum ? What is said 
Of the lateral diameter of the chest ? Explain fig. 95. 



PHYSIOLOGY OF THE RESPIRATORY ORGANS. 219 

the third has still more than the second. The second rib is 
elevated by the contraction of the muscles between it and the 
first. The third rib is raised by the action of two sets of 
muscles ; one lies between the first and second ribs, the other 
between the second and third. The motion of each succeed- 
ing rib is increased, because it is not only acted upon by the 
muscles that move the ribs above, but by an additional inter- 
costal ; so that the movement of the twelfth rib is very free, 
as it is elevated by the contraction of eleven muscles. 

479. The tenth rib is raised eight times as much as the 
second rib, and the lateral diameter of the lower portion of the 
chest is increased in a corresponding degree. At the same 
time, the muscular margin of the diaphragm contracts, which 
depresses its central portion ; and in this way, the chest is 
enlarged forward, laterally, and downward, simultaneously 
with the relaxation of the walls of the abdomen. 

480. The lungs follow the variations of capacity in the 
chest, expanding their air-cells when the latter is enlarged, 
and contracting when the chest is diminished. Thus, when 
the chest is expanded, the lungs follow, and consequently a 
vacuum is produced in their air-cells. The air then rushes 
through the mouth and nose into the trachea and its branches, 
and fills the vacuum as fast as it is made. This mechanical 
process constitutes inspiration. 

481. After the expansion of the chest, the muscles that 
elevated the ribs relax, together with the diaphragm. The 
elasticity of the cartilages of the ribs depresses them, 
and the cavity of the chest is diminished, attended by the 
expulsion of a portion of the air from the lungs. At the 
same time, the muscles that form the front walls , of the 

478. Describe the action of the intercostal muscles upon' the ribs. 

479. How does the elevation of the tenth rib compare with the second ? 
What effect has this elevation upon the lateral diameter of the chest ? 

480. Describe the process of inspiration. 481. Describe the process by 
which the air is forced out of the lungs. 



220 



ANATOMY, PHYSIOLOGY, AND HYGIENE. 



abdominal cavity, contract, and press the alimentary canal, 
stomach, and liver, upward against the diaphragm ; this, being 
relaxed, yields to the pressure, rises upward, and presses 
upon the lungs, which retreat before it, and another portion 
of air is expelled from these organs. This process is called 
expiration. 

Fig. 96. 




Fig. 96. A front view of the chest and abdomen in respiration. 1, 1, The position 
of the walls of the chest in inspiration. 2, 2, 2, The position of the diaphragm in 
inspiration 3, 3, The position of the walls of the chest in expiration. 4, 4, 4, The 
position of the diaphragm in expiration. 5, 5, The position of the walls of the abdo- 
men in inspiration. 6, 6, The position of the abdominal walls in expiration. 

482. Thus it is obvious that the enlargement of the chest, 
or inspiration, is produced in two ways : 1st. By the depres- 
sion of the convex portion of the diaphragm ; 2d. By the 
elevation of the ribs. On the contrary, the contraction of the 



Explain fig. 96. 482. In how many ways may the chest be enlarged, and 
how is it accomplished ? How is the contraction of the chest effected ? 



PHYSIOLOGY OF THE RESPIRATORY ORGANS. 



221 



chest, or expiration, is produced by the depression of the ribs, 
and elevation of the central part of the diaphragm. These 
movements are successive during life, and constitute res- 
piration. 

Fig. 97. 




Fig. 97. A -side view of the chest and ahdomen in respiration. 1, The cavity of 
the chest. 2, The cavity of the ahdomen. 3, The line of direction for the diaphragm 
when relaxed in expiration. 4, The line of direction for the diaphragm when con- 
tracted in inspiration. 5, 6, The position of the front walls of the chest and abdo- 
men in inspiration. 7, 8, The position of the front walls of the abdomen and chest 
in expiration. 



Experiment. Place the ear upon the chest of a person, 
and a murmuring sound will be heard, somewhat like the soft 
sighings of the wind through forest trees. This sound is 



Explain fig. 97. How may the murmur of respiration be heard 

19* 



222 ANATOMY, PHYSIOLOGY, AND HYGIENE. 

caused by the air rushing in and out of the lungs, and is 
peculiarly distinct in the child. 

483. It is not easy to decide how much air is taken into 
the lungs at each inspiration. The quantity, however, must 
vary in different individuals, from the difference in the condi- 
tion and expansion of the lungs, together with the size of the 
chest. From numerous experiments, the quantity, at an 
ordinary inspiration, of a common-sized man, is fixed at forty 
cubic inches. It has also been shown that one hundred and 
seventy cubic inches can be thrown out of the lungs by a for- 
cible expiration, and that there remain in the lungs two hun- 
dred and twenty cubic inches ; so that these organs, in their 
quiescent state, may be considered as containing about three 
hundred and ninety cubic inches of air, or more than a gallon. 

484. Respiration is more frequent in females and children 
than in adult men. In diseases, particularly those of the 
lungs, it is more increased in frequency than the action of the 
heart. In health, the smallest number of inspirations in a 
minute by an adult, is not less than fourteen, and they rarely 
exceed twenty-five. Eighteen may be considered an average 
number. The quantity of oxygen taken into the lungs at 
each inspiration is about four cubic inches, one half of which 
disappears in every act of respiration. 

Observation. Under different circumstances, however, the 
consumption of oxygen varies. It is greater when the tem- 
perature is low, than when it is high ; and during digestion, 
the consumption has been found one half greater than when 
the stomach was empty. 

483. Can it be ascertained with accuracy how much air is taken into the 
lungs at each inspiration ? Why not ? "What is the probable quantity 
that an ordinary sized man inspires ? How much can be thrown out of 
the lungs at a forcible expiration, and how mucb remains in the lungs ? 
From these calculations, how much may they contain in their quiescent 
state ? 484. In whom is respiration most frequent ? How in disease ? 
How in health ? How many may be considered an average number ? 
When is the consumption of oxygen the greatest ? 



PHYSIOLOGY OF THE RESPIRATORY ORGANS. 223 

485. Dr. Southwood Smith has lately performed a series 
of very interesting experiments, from which he deduces the 
following general results : " 1st. The volume of air ordinarily 
present in the lungs is about twelve pints. 2d. The volume 
of air received by the lungs at an ordinary inspiration is one 
pint. 3d. The volume of air expelled from the lungs at an 
ordinary expiration, is a little less than one pint. 4th. Of the 
volume of air received by the lungs at one inspiration, only 
one fourth part is decomposed at one action of the heart. 
5th. The quantity of blood that flows to the lungs, to be acted 
upon by the air at one action of the heart, is two ounces, and 
this is acted on in less than one second of time. 6th. The 
quantity of blood in the whole body of the human adult, is 
twenty-five pounds avoirdupois, or twenty pints. 7th. In the 
mutual action that takes place between the air and blood, 
every twenty-four hours, the air loses* thirty-seven ounces 
of oxygen, and the blood fourteen ounces of carbon." 

486. Apparently, atmospheric air is a simple element. 
But chemical analysis shows its composition to be oxygen and 
nitrogen, in the proportion of twenty-one parts of the former, 
and about seventy-nine of the latter. In addition, there is a 
small amount of vapor and carbonic acid. The pressure of 
this invisible, elastic fluid upon the body of an ordinary sized 
adult, is estimated to equal thirty-five thousand pounds. 

487. The principal substances of a vitiated character in 
the dark-colored blood, are carbonic acid and w T ater. Although 
there is a strong affinity between the oxygen and nitrogen of 
the air, yet the former has a stronger affinity for blood, than 
for nitrogen. Hence, whenever blood is presented to the 



485. State the 1st, 2d, 3d, and 4th deductions from the experiments of 
Dr. Southwood Smith. The oth, 6th, and 7th. 486. Of what is atmos- 
pheric air composed ? What is the weight of air upon a common sized 
man ? 487. "What is said of the affinity of carbonic acid, water, and 
oxygen ? What is said of the chemical affinity between oxygen and 
nitrogen ? 



224 ANATOMY, PHYSIOLOGY, AND HYGIENE. 

air in the lungs, the oxygen leaves the nitrogen, and becomes 
mixed with the circulating fluid. 

488. Again, carbonic acid and water have a stronger 
affinity for atmospheric air than for the other elements of the 
blood. Consequently, when they are brought into contact 
with the air in the lungs, the carbonic acid and water leave 
the other constituents of the blood, and unite with the air. In 
this way the bluish, or impure blood is relieved of its impu- 
rities, and becomes the red, or pure blood, which contains the 
principles so essential to life. 

489. The formation of carbonic acid and water, eliminated 
from the system through the lungs and skin, is explained by 
the following theory : In the lungs and upon the skin the 
oxygen separates from the nitrogen and unites with the blood 
in the capillary vessels of these organs. The oxygen is con- 
veyed with the blood to the capillary arteries and veins of the 
different tissues of the system. In these membranes there is 
a chemical union of the oxygen with the carbon and hydrogen 
contained in the chyle and waste atoms of the body. This 
combustion, or union of oxygen with carbon and hydrogen, is 
attended with the disengagement of heat, and the formation 
of carbonic acid and water. 

4S0. The following experiment will illustrate the passage 
of fluids through membranes, and the different affinity of 
gases for each other. Put a mixture of water and alcohol 
into a phial and leave it uncorked. Both the water and 
alcohol have a greater affinity for air than for each other. 
Alcohol has a greater affinity for the air, and will be diffused 
through it more readily than the water, when there is no 
intervening obstacle. But tie a piece of bladder over the 
mouth of the phial, and let it stand a few days, — the water 

488. What is formed when oxygen unites with carbon or hydrogen ? 
489. Give the theory for the formation of carbonic acid and watery vapor 
thrown ont of the system. 490. Illustrate the passage of fluids through 
membranes, and the different affinities of gases. 



PHYSIOLOGY OF THE RESPIRATORY ORGANS. 225 

will leave the alcohol, and pass through the membrane. By 
the aid of this experiment, we shall endeavor to explain the 
interchange of fluids in the lungs. 

491. The walls of the air-vesicles, and coats of the blood- 
vessels, are similar, in their mechanical arrangement, to the 
membranous bladder in the before described experiment. 
As the oxygen of the air has greater affinity for blood than for 
nitrogen, so it permeates the membranes that intervene be- 
tween the air and blood more readily than the nitrogen. 
As the carbonic acid and water have a greater affinity for 
air than for the other elements of the blood, so they will also 
pass through the walls of the blood-vessels and air-cells more 
readily than the other elements of the dark-colored blood. 

Fig. 98. 




Fig. 98. 1, A bronchial tube divided into three branches. 2, 2, 2, Air-cells. 

3, Branches of the pulmonary artery, that spread over the air-cells. Through the 
pulmonary artery the dark, impure blood is carried to the air-cells of the lungs. 

4, Branches of the pulmonary vein, that commence at the minute terminations of the 
pulmonary artery. Through the pulmonary vein the red blood is returned to the heart. 

492. As the impure blood is passing in the minute vessels 
over the air-cells, the oxygen passes through the thin coats of 
the air-cells and blood-vessels, and unites with the blood. At 
the same time, the carbonic acid and water leave the blood, 
and pass through the coats of the blood-vessels and air-cells, 
and mix with the air in the cells. These are thrown out of the 
system every time we breathe. This interchange of products 
produces the change in the color of the blood. 

Explain fig. 98. 492. How and where is the blood changed ? 



226 



ANATOMY, PHYSIOLOGY, AND HYGIENE. 



Experiment. Fill a bladder with dark blood drawn from 
any animal. Tie the bladder closely, and suspend it in the 
air. In a few hours, the blood next the membrane will have 
become of a bright red color. This is owing to the oxygen 
from the air passing through the bladder, and uniting with 
the blood, while the carbonic acid has escaped through the 
membrane. 

Fig. 99. 




Fig. 99. An ideal view of the pulmonary circulation. 1, 1, The right lung. 
2, 2, The left lung. 3, The trachea. 4, The right bronchial tube. 5, The left 
bronchial tube. 6, 6, 6, 6, Air-cells. 7, The right auricle. 8, The right ventricle. 
9, The tricuspid valves. 10, The pulmonary artery. 11, The branch to the right 
lung. 12, The branch to the left lung. 13, The right pulmonary vein. 14, The 
left pulmonary vein. 15, The left auricle. 16, The left ventricle. 17, The 
mitral valves. 

493. The presence of carbonic acid and watery vapor in 
the expired air, can be proved by the following experiments : 

Give the experiment showing that oxygen changes the dark-colored 
blood to a bright red color. What is represented by fig. 99 ? 493. How can 
the presence of carbonic acid in the lungs be proved ? 



PHYSIOLOGY OF THE RESPIRATORY ORGANS. 227 

1st. Breathe into Hme-water, and in a few minutes it will 
become of a milk-white color. This is owing to the carbonic 
acid of the breath uniting with the lime, forming the car- 
bonate of lime. 2d. Breathe upon a cold, dry mirror for a 
few minutes, and it will be covered with moisture. This is 
condensed vapor from the lungs. In warm weather, this 
watery vapor is invisible in the expired air, but in a cold, dry 
morning in winter, the successive jets of vapor issuing from 
the mouth and nose are sufficiently obvious. 

494. From the lungs are eliminated other impurities be- 
side carbonic acid, the perceptible quality of which is various 
in different persons. The offensive breath of many persons 
may be caused by decayed teeth, or the particles of food that 
may be retained between them, but it often proceeds from the 
secretion, in the lungs, of certain substances which previously 
existed in the system. 

Illustration. When spirituous liquors are taken into the 
stomach, they are absorbed by the veins and mixed with the 
dark-colored blood, in which they are carried to the lungs to 
be expelled from the body. This will explain the fact, which 
is familiar to most persons, that the odor of different sub- 
stances is perceptible in the breath, or expired air, long after 
the mouth is free from these substances. 



How the watery vapor ? 494. Are there other excretions from the lungs ? 
Give the illustration. 

Note. Let the anatomy and physiology of the respiratory organs be 
reviewed from rigs. 96, 97, and 99, or from anatomical outline plates Nos. 
5 and 7. 



228 ANATOMY, PHYSIOLOGY," AND HYGIENE. 

CHAPTER XXV. 

HYGIENE OF THE RESPIRATORY ORGANS. 

495. For man to enjoy the highest degree of health, it 
is necessary that the impure " venous " blood be properly 
changed. As this is effected in the lungs by the action of the 
air, it follows that this element, when breathed, should be 
pure, or contain twenty-one per cent, of oxygen to about 
seventy-nine per cent, of nitrogen. 

496. The volume of air expelled from the lungs is some- 
what less than that which is inspired. The amount of loss 
varies under different circumstances. An eightieth part of 
the volume taken into the lungs, or half a cubic inch, may be 
considered an average estimate. 

497. The quality and purity of the air is affected by every 
respiration. 1st. The quantity of oxygen is diminished. 
2d. The amount of carbonic acid is increased. 3d. A certain 
proportion of watery vapor is ejected from the lungs in the 
expired air. Of the twenty-one parts of oxygen in the 
inspired air, only eighteen parts are expired, while the car- 
bonic acid and watery vapor are increased about four per 
cent. The quantity of nitrogen is nearly the same in the 
expired as in the inspired air. 

Observation. It is now fully ascertained that while the 
chemical composition of the blood is essentially changed, its 

495 — 546. Give the hygiene of the respiratory organs. 495. What is 
necessary that man enjoy the highest degree of health ? 496. How does 
the volume of expired air compare with that which was inspired ? Does 
this loss vary, and what is an average estimate ? 497. How is the purity 
of the air affected by respiration ? How is the inhaled oxygen affected ? 
"What effect on the carbonic acid and watery vapor ? On the nitrogen ? 
"What is said respecting the weight of the blood ? 



HYGIENE OF THE RESPIRATORY ORGANS. 229 

weight remains the same, as the carbon and hydrogen dis- 
charged are equal to the united weight of the oxygen and 
nitrogen absorbed. 

498. If one fourth part of the volume of air received by 
the lungs at one inspiration is decomposed at one " beat " 
of the heart, it might be supposed that if the expired air be 
again received into the lungs, one half of the oxygen would 
be consumed, and, in a similar ratio, if re-breathed four times, 
all the oxygen would be consumed. But it does not follow, if 
the air is thus re-breathed, that the same changes will be 
effected in the lungs. For air that has been inspired does 
not part with its remaining oxygen as freely as when it con- 
tains the proper amount of this life-giving element, and thus 
the changes in the impure blood are not so completely effected. 

Illustration. In the process of dyeing, each successive 
article immersed in the dye weakens it ; but it does not 
follow that the dye each time is affected in the same degree, 
or that the coloring matter by repeated immersions can be 
wholly extracted. The same principle applies to the exchange 
of oxygen and carbonic acid gas in the lungs. 

499. If the inspired air is free from moisture and carbonic 
acid, these substances contained in the blood will be more 
readily imparted to it. When the air is loaded with vapor, they 
are removed more slowly ; but if it is saturated with moisture, 
no vapor will escape from the blood through the agency of the 
lungs. This may be illustrated by the following experiment : 
Take two and a half pounds of water, add to it half a pound of 
common salt, (muriate of soda,) and it will readily mix with 
the water ; and to this solution add the same quantity of salt, 
and it will be dissolved more slowly. Again, add more salt, 
and it will remain undissolved, as the water has become 
saturated by the pound before dissolved. 

498. Does air that is re-breathed freely impart its oxygen ? Why ? 
499. "What is the effect on the blood when the air is free from vapor and 
carbonic acid ? When loaded with vapor ? When saturated ? How is this 
illustrated ? 

20 



230 ANATOMY, PHYSIOLOGY, AND HYGIENE. 

500. The principle in this experiment is analogous to that 
of the union between carbonic gas and atmospheric air. 
Allen and Pepy showed by experiment, that air which had 
been once breathed, contained eight and a half per cent, of 
carbonic acid. They likewise showed, that no continuance of 
the respiration of the same air could make it take up more 
than ten per cent. This is the point of saturation. 

Experiment. Sink a glass jar that has a stop-cock, or one 
with a glass stopper, into a pail of water, until the air is expelled 
from the jar. Fill the lungs with air, and retain it in the 
chest a short time, and then breathe into the jar, and instantly 
close the stop-cock. Close the opening of the jar that is under 
the water with a piece of paper laid on a plate of sufficient 
size to cover the opening, invert the jar, and sink into it a 
lighted candle. The flame will be extinguished as quickly 
as if put in water.* Remove the carbonic acid by inverting 
the jar, and place a lighted candle in it, and the flame will be 
as clear as when out of the jar. 

Observations. 1st. It is familiarly known that a taper will 
not burn where carbonic acid exists in any considerable 
quantity, or when there is a marked deficiency of oxygen. 
From this originated the judicious practice of sinking a lighted 
candle into a well or pit before descending into it. If the 
flame is extinguished, respiration cannot there be maintained, 
and life would be sacrificed should a person venture in, until 
the noxious air is removed. 

2d. It is the action of carbonic acid upon the respiratory 



* As a substitute for a jar with a stop-cock, take a piece of lead pipe 
bent in the form of a siphon, and insert it in the mouth of a reversed 
jar. This experiment is as conclusive whether the air is inhaled once 
only or breathed many times. 

500. What did the experiments of Allen and Pepy show ? How can the^ 
presence of carbonic gas in the expired air be demonstrated ? State obser- 
vation 1st. Observation 2d. 



HYGIENE OF THE RESPIRATORY ORGANS. 231 

organs, that gives rise to a phenomenon frequently seen in 
mines and caves. A man may enter these subterranean 
rooms, and feel no inconvenience in breathing ; but the dog 
that follows him, falls apparently dead, and soon dies if not 
speedily removed to pure air. This arises from the fact that 
this gas is heavier than air, and sinks to the bottom of the 
room or cave. 

3d. While it is true that carbonic acid possesses properties 
that render it unfit to be breathed, it is, notwithstanding, 
productive of very agreeable effects, when conveyed into 
the stomach. It forms the sparkling property of mineral 
waters, and fills the bubbles that rise when beer or cider is 
fermenting. 

501. Pure atmospheric air is best adapted to a healthy 
action of the system. As the air cannot be maintained pure 
under all circumstances, the question may be asked, To what 
degree may the air be vitiated and still sustain life ? and 
what is the smallest quantity of pure air a person needs each 
minute to maintain good health ? Birnan says, that air which 
contains more than three and a half per cent, of carbonic 
acid is unfit for respiration, and, as air once respired contains 
eight and a half per cent, of carbonic acid, it clearly shows 
that it is not fitted to be breathed again. 

502. No physiologist pretends that less than seven cubic 
feet of air are adequate for a man to breathe each minute, 
w T hile Dr. Reid allows ten feet. The necessity of fifteen or 
twenty times the amount of air actually taken into the lungs, 
arises from the circumstance, that the expired air mixes 
with and vitiates the surrounding element that has not been 
inhaled. 

503. The quantity of air which different persons actually 

Observation 3d. 501. What questions may be asked respecting the 
inspired air? Give the remark of Birnan. 502. How many cubic feet of 
air are adequate for a man to breathe each minute ? How much does Dr. 
Eeid allow ? 503. Mention some reasons why different persons do not 
require the same amount of air. 



232 ANATOMY, PHYSIOLOGY, AND HYGIENE. 

need, varies. The demand is modified by the size, age, 
habits, and condition of the body. A person of great size 
who has a large quantity of blood, requires more air than a 
small man with a less amount of circulating fluid. Individuals 
whose labor is active, require more air than sedentary or idle 
persons, because the waste of the system is greater. On the 
same principle, the gormandizer needs more of this element 
than the person of abstemious habits. So does the growing 
lad require more air than an adult of the same weight, for 
the reason that he consumes more food than a person of 
mature years. Habit also exerts a controlling influence. A 
man who works in the open air suffers more when placed in 
a small, unventilated room, than one who is accustomed to 
breathe the confined air of workshops. 

504. Air, in which lamps will not burn witli brilliancy, is 
unfitted for respiration. In crowded rooms, which are not 
ventilated, the air is vitiated, not only by the abstraction of 
oxygen and the deposition of carbonic acid, but by the excre- 
tions from the skin and lungs of the audience. The lamps, 
under such circumstances, emit but a feeble light. Let the 
oxygen gas be more and more expended, and the lamps will 
burn more and more feebly, until they are extinguished. 

Illustrations. 1st. The effects of breathing the same air 
again and again, are well illustrated by an incident that 
occurred in one of our halls of learning. A large audience 
had assembled in an ill-ventilated room, to listen to a lecture ; 
soon the lamps burned so dimly that the speaker and audience 
were nearly enveloped in darkness. The oppression, diz- 
ziness, nnd faintness experienced by many of the audience, 
induced them to leave, and in a few minutes after, the lamps 
were observed to rekindle, owing to the exchange of pure air 
on opening the door. 

How is it with the laborer ? "With the gormandizer ? "With the person 
that works in the open air ? 504. What effect has impure air on a burning 
lamp ? Give the illustration of the effects of impure air on lighted lamps. 



HYGIENE OF THE RESPIRATORY ORGANS. 233 

2d. In the "Black Hole of Calcutta," one hundred and 
forty-six Englishmen were shut up in a room eighteen feet 
square, with only two small windows on the same side to admit 
air. On opening this dungeon, ten hours after their imprison- 
ment, only twenty-three were alive. The others had died 
from breathing impure air. 

505. Air that has become impure from the abstraction of 
oxygen, an excess of carbonic acid, or the excretions from the 
lungs and skin, has a deleterious effect on the body. When 
this element is vitiated from the preceding causes, it prevents 
the proper arterialization, or change in the blood. For this 
reason, pure air should be admitted freely and constantly into 
work-shops and dwelling-houses, and the vitiated air permitted 
to escape. This is of greater importance than the warming 
of these apartments. We can compensate for the deficiency 
of a stove, by an extra garment or an increased quantity of 
food ; but neither garment, exercise, nor food will compensate 
for pure air. 

506. School-rooms should be ventilated. If they are not, 
the pupils will be restless, and complain of languor and head- 
ache. These unpleasant sensations are caused by a want of 
pure air, to give an adequate supply of oxygen to the lungs. 
W r hen pupils breathe for a series of years such vitiated air, 
their life is undoubtedly shortened, by giving rise to consump- 
tion and other fatal diseases. 

Illustration. A school-room thirty feet square and eight 
feet high, contains 7200 cubic feet of air. This room will 
seat sixty pupils, and, allowing ten cubic feet of air to each 
pupil per minute, all the air in the room will be vitiated in 
twelve minutes. 

Observation. In all school-rooms where there is not ade- 



Of the effects of breathing impure air. 505. In preserving health, what 
is of greater importance than warming the room ? 506. "Why should a 
school-room be ventilated ? Give the illustration. 

20 * 



234 ANATOMY, PHYSIOLOGY, AND HYGIENE. 

quate ventilation, it is advisable to have a recess of five or 
ten minutes each hour. During this time, let the pupils 
breathe fresh air, and open the doors and windows, so that the 
air of the room shall be completely changed. 

507. Churches, concert halls, and all rooms designed for 
a collection of individuals, should be amply ventilated. While 
the architect and workmen are assiduous in giving these public 
rooms architectural beauty and splendor, by adorning the 
ceiling with Gothic tracery, rearing richly carved columns, 
and providing carefully for the warming of the room, it too 
frequently happens that no direct provision is made for the 
change of that element which gives us beauty, strength, 
and life. 

Illustration. A hall sixty feet by forty, and fifteen feet 
high, contains 36,000 cubic feet of air. A hall of this size 
will seat four hundred persons; by allowing ten cubic feet of 
air to each person per minute, the air of the room will be 
rendered unfit for respiration in nine minutes. 

508. Railroad cars, cabins of steam and canal-boats, omni- 
buses, and stage-coaches, require ample ventilation. In the 
construction of these public conveyances, too frequently, the 
only apparent design is, to seat the greatest number of persons, 
regardless of the quantity and character of the air to maintain 
health and even life. The character of the air is only realized 
when, from the fresh, pure air, we enter a crowded cabin of 
a boat or a closed coach ; then the vitiated air from animal 
excretions and noxious gases is offensive, and frequently pro- 
duces sickness. 

509. The influence of habit is strikingly expressed by 
Birnan, in the " Art of Warming and Ventilating Rooms : " 
" Not the least remarkable example of the power of habit is 

"What suggestion when a school-room is not ventilated ? 507. What is 
said in regard to ventilating churches, concert halls, &c. ? State the 
illustration. 508. What remarks relative to public conveyances ? 509. State 
the influence of habit by Birnan. 



HYGIENE OF THE RESPIRATORY ORGANS. 235 

its reconciling us to practices which, but for its influence, 
would be considered noxious and disgusting. We instinctively 
shun approach to the dirty, the squalid, and the diseased, and 
use no garment that may have been worn by another. We 
open sewers for matters that offend the sight or the smell, and 
contaminate the air. We carefully remove impurities from 
what we eat and drink, filter turbid water, and fastidiously 
avoid drinking from a cup that may have been pressed to the 
lips of a friend. On the other hand, we resort to places of 
assembly, and draw into our mouths air loaded with effluvia 
from the lungs, skin, and clothing of every individual in the 
promiscuous crowd — exhalations offensive, to a certain extent, 
from the most healthy individuals ; but when arising from a 
living mass of skin and lungs, in all stages of evaporation, 
disease, and putridity, — prevented by the walls and ceiling 
from escaping, — they are, when thus concentrated, in the 
highest degree deleterious and loathsome." 

510. The sleeping-room should he so ventilated that the air 
in the morning will he as pure as when retiring to rest in the 
evening. Ventilation of the room would prevent morning 
headaches, the want of appetite, and languor — so common 
among the feeble. The impure air of sleeping-rooms proba- 
bly causes more deaths than intemperance. Look around the 
country, and those who are most exposed, who live in huts 
but little superior to the sheds that shelter the farmer's flocks, 
are found to be the most healthy and robust. Headaches, liver 
complaints, coughs, and a multitude of nervous affections, are 
almost unknown to them ; not so with those who spend their 
days and nights in rooms in which the sashes of the windows 
are calked, or perchance doubled, to prevent the keen but 
healthy air of winter from entering their apartments. Disease 
and suffering are their constant companions. 



510. What is said of the ventilation of sleeping-rooms ? What would 
adequate ventilation prevent ? Give a common observation. 



236 ANATOMY, PHYSIOLOGY, AND HYGIENE. 

Illustration. By many, sleeping apartments twelve feet 
square and seven feet high, are considered spacious for two 
persons, and good accommodations for four to lodge in. An 
apartment of this size contains 1008 cubic feet of air. Al- 
lowing ten cubic feet to each person per minute, two occupants 
would vitiate the air of the room in fifty minutes, and four in 
twenty-five minutes. When lodging- rooms are not ventilated, 
we would strongly recommend early rising. 

511. The sick-room, particularly, should be so arranged 
that the impure air may escape, and pure air be constantly ad- 
mitted into the room. It is no unusual practice in some com- 
munities, when a child or an adult is sick of an acute disease, 
to prevent the ingress of pure air, simply from the apprehen- 
sion of the attendants, that the patient will contract a cold. 
Again, the prevalent custom of several individuals sitting in 
the sick-room, particularly when they remain there for several 
hours, tends to vitiate the air, and, consequently, to increase 
the suffering and danger of the sick person. In fevers or 
inflammatory diseases of any kind, let the patient breathe 
pure air; for the purer the blood, the greater the power of the 
system to remove disease, and the less the liability to con- 
tract colds. 

Observation. Among children, convulsions, or " fits," usu- 
ally occur when they are sleeping. In many instances, these 
are produced by the impure air which is breathed. To pre- 
vent these alarming and distressing convulsions, the sleeping- 
room should be ventilated, and there should be no curtains 
around the bed, or coverings over the face, as they produce 
an effect similar to that experienced when sleeping in a small, 
unventilated room. To relieve a child when convulsed, carry 
it into the open air. 

512. While occupying a room, we are insensible of the 

What is said of the size of sleeping-rooms ? 511. What is said of the 
sick-room ? Mention some prevailing customs in reference to these 
rooms. What is said of convulsions among children ? 



HYGIENE OF THE RESPIRATORY ORGANS. 237 

gradual vitiation of the air. This is the result of the dimin- 
ished sensibility of the nervous system, and gradual adaptation 
of the organs to blood of a less stimulating character. This 
condition is well illustrated in the hibernating animals. We 
are insensible of the impure air of unventilated sleeping-rooms, 
until we leave them for a walk or ride. If they have been 
closed, we are made sensible of the character of the air as 
soon as we reenter them, for the system has regained its usual 
sensibility while inhaling a purer atmosphere. 

513. In the construction of every inhabited room, there 
should be adequate means of ventilation, as well as warming. 
No room is well ventilated, unless as much pure air is brought 
into it as the occupants vitiate at every respiration. This can 
be effected by making an aperture in the ceiling of the room, 
or by constructing a ventilating flue in the chimney. This 
should be in contact with the flues for the escape of smoke, 
but separated from them by* a thin brick partition. The hot 
air in the smoke flues will warm the separating brick partition, 
and consequently rarefy the air in the ventilating flue. Com- 
munication from every room in a house should be had to such 
flues. The draught of air can be regulated by well-adjusted 
registers, which in large rooms should be placed near the floor 
as well as near the ceiling. 

514. While provision is made for the escape of rarefied 
impure air, we should also provide means by which pure air 
may be constantly admitted into the room, as the crevices of 
the doors and windows are not always sufficient ; and, if they 
should be adequate, air can be introduced in a more conven- 
ient, economical, and appropriate manner. There should be 
an aperture opposite the ventilating flue, at or near the floor, 
to connect with the outer walls of the building or external air. 

512. Why are we insensible to the gradual vitiation of the air of an un- 
ventilated room ? 513. What is very important in the building of every 
inhabited room ? How can a room be well ventilated ? 514. What is said 
relative to a communication with the external air ? 



238 ANATOMY, PHYSIOLOGY, AND HYGIENE. 

But if pure heated air is introduced into the room, it obviates 
the necessity of the introduction of the external air.* 

515. In warming rooms, the hot air furnaces, or box and 
air-tight stoves converted into hot air furnaces, should be 
used in preference to the ordinary stoves. The air thus intro- 
duced into the room is pure as well as warm. In the adapta- 
tion of furnaces to dwelling-houses, &c, it is necessary that 
the air should pass over an ample surface of iron moderately 
heated ? as a red heat abstracts the oxygen from the contigu- 
ous air, and thus renders it unfit to be respired. f 

Observation. Domestic animals need a supply of pure air 
as well as man. The cows of cities, that breathe a vitiated 
air, have, very generally, tubercles. Sheep that are shut in 
a confined air, die of a disease called the " rot," which is of 
a turberculous character. Interest and humanity require that 
the buildings for animals be properly ventilated. 



* Mr. Frederick Emerson, of Boston, has devised a simple and 
effective apparatus for removing vitiated air from a room. It is suc- 
cessfully used upon all the public school-houses of Boston. It is now 
being generally applied to the school-houses and other public build- 
ings, as well as private dwellings, of New England. 

f Dr. Wyman's valuable work on " Ventilation," and the work of 
Henry Barnard, Esq., on "School-house architecture," can be advanta- 
geously consulted, as they give the practical methods of ventilating 
and warming shops, school-rooms, dwelling-houses, public halls, &c. 

515. How should rooms be warmed ? What is necessary in the adapta- 
tion of furnaces to dwelling-houses ? 



HYGIENE OF THE RESriRATORY ORGANS. 239 



CHAPTER XXYI. 

HYGIENE OE THE RESPIRATORY ORGANS, CONTINUED. 

516. The change that is effected in the blood while passing 
through the lungs, not only depends upon the purity of the 
air, but the amount inspired. The quantity varies according 
to the size of the chest, and the movement of the ribs and 
diaphragm. 

517. The size of the chest and lungs can he reduced by 
moderate and continued pressure. This is most easily done 
in infancy, when the cartilages and ribs are very pliant ; yet 
it can be effected at more advanced periods of life, even after 
the chest is fully developed. For want of knowledge of the 
pliant character of the cartilages and ribs in infants, too many 
mothers, unintentionally, contract their chests, and thus sow 
the seeds of disease by the close dressing of their offspring. 

518. If slight but steady pressure be continued from day 
to day and from week to week, the ribs will continue to yield 
more and more, and after the expiration of a few months, 
the chest will become diminished in size. This will be 
effected without any suffering of a marked character ; but 
the general health and strength will be impaired. It is not 
the violent and ephemeral pressure, but the moderate and 
protracted, that produces the miscalled, " genteel," con- 
tracted chests. 

519. The style of dress which at the present day is almost 
universal, is a prolific cause of this deformity. These bane- 

516. What varies the amount of air received into the lungs ? 517. How 
can the size of the chest be diminished ? "When is this most easily effected ? 
518. How are the miscalled, "genteel," contracted chests usually pro- 
duced ? 519. What is said of the style of the dress at the present day ? 



240 



ANATOMY, PHYSIOLOGY, AND HYGIENE. 



ful fashions are copied from the periodicals, so widely cir- 
culated, containing a "fashion plate of the latest fashions, 
from Paris." In every instance, the contracted, deformed, 
and, as it is called, lady-like waist, is portrayed in all its 
fascinating loveliness. These periodicals are found on almost 
every centre-table, and exercise an influence almost omnip- 
otent. If the plates which corrupt the morals are excluded 
by civil legislation, with the same propriety ought not those to 
be suppressed that have a tendency so adverse to health ? 



Fig. 100. 



Fig. 101. 




Fig. 100. A correct outline of the Venus de Medici, the beau ideal of female 
symmetry. 

Fig. 101. An outline of a well-corseted modern beauty. 

One has an artificial, insect waist ; the other, a natural waist. One has sloping 
shoulders, while the shoulders of the other are comparatively elevated, square, and 
angular. The proportion of the corseted female below the waist, is also a departure 
from the symmetry of nature. 

Observations. 1st. The Chinese, by compressing the feet 
of female children, prevent their growth ; so that the foot of a 

What does fig. 100 represent ? Fig. 101 ? Give observation 1st. 



HYGIENE OF THE RESPIRATORY ORGANS. 241 

Chinese belle is not larger than the foot of an American girl 
of five years. 

2d. The American women compress their chests, to prevent 
their growth ; so that the chest of an American belle is not 
larger than the chest of a Chinese girl of five years. Which 
country, in this respect, exhibits the greater intelligence ? 

3d. The chest can be deformed by making the linings of 
the waists of the dresses tight, as well as by corsets. Tight 
vests, upon the same principle, are also injurious. 

520. In children, who have never worn close garments, 
the circumference of the chest is generally about equal to that 
of the body at the hips ; and similar proportions would exist 
through life, if there were no improper pressure of the 
clothing. This is true of the laboring women of the Emerald 
Isle, and other countries of Europe, and in the Indian female, 
whose blanket allows the free expansion of the chest. The 
symmetrical statues of ancient sculptors bear little resem- 
blance to the " beau ideal " of American notions of elegant 
form. This perverted taste is in opposition to the laws of 
nature. The design of the human chest is not simply to 
connect the upper and lower portions of the body, like some 
insects, but to form a case for the protection of the vital 
organs. 

521. Individuals may have small chests from birth. This, 
to the particular individual, is natural ; yet it is adverse to the 
great and general law of Nature relative to the size of the 
human chest. Like produces like, is a general law of the 
animal and vegetable kingdoms. No fact is better estab- 
lished, than that which proves the hereditary transmission 



Observation 2d. Observation 3d. 520. What is the size of the chest of 
a child that has always worn loose clothing ? What is said of the size of 
the laboring women of Ireland, and the Indian female? How is it in 
ancient statues ? What is the design of the chest ? 521. What is a gen- 
eral law of both the animal and vegetable kingdoms ? What fact in this 
connection is well established ? 
21 



242 ANATOMY, PHYSIOLOGY, AND HYGIENE. 

from parents to children of a constitutional liability to disease ; 
and the same may be said in regard to their conformations. 
If the mother has a small, taper waist, either hereditary or 
acquired, this form may be impressed on her offspring ; — thus 
illustrating the truthfulness of scripture, " that the sins of the 
parents shall be visited upon the children unto the third and 
fourth generation." 

522. The quantity of air inhaled is modified by the capa- 
city of the respiratory organs. The necessity of voluminous 
lungs may be elucidated by the following experiment : Sup- 
pose a gill of alcohol, mixed with a gill of water, be put into 
a vessel having a square foot of surface, and over the vessel 
a membrane be tied, and that the water will evaporate in 
twenty-four hours. If the surface had been only six inches 
square, only one fourth of the water would have evaporated 
through the membrane in the given time. If the surface had 
been extended to two square feet, the water would have evap- 
orated in twelve hours. 

523. Apply this principle to the lungs : suppose there are 
two hundred feet of carbonic acid to be carried out of the 
system every twenty-four hours. This gas, in that time, will 
pass through a vesicular membrane of two thousand square 
feet. If the lungs were diminished in size, so that there would 
be only one thousand square feet of vesicular membrane, the 
amount of carbonic acid would not, and could not, be eliminated 
from the system. Under such circumstances, the blood would 
not be purified. 

524. Again ; suppose the two thousand square feet of 
membrane would transmit two hundred cubic feet of oxygen 
into the system every twenty-four hours. If it should be 
diminished one half, this amount of oxygen would not pass 
into the blood. From the above illustrations we may learn 

"What does this hereditary transmission prove ? 522. How is the 
necessity of voluminous lungs illustrated ? 523. How is this principle 
applied to the interchange of products in the lungs ? 



HYGIENE OF THE RESPIRATORY ORGANS. 243 

the importance of well-developed chests and voluminous 
lungs ; for, by increasing the size of the lungs, the oxygen is 
more abundantly supplied to the blood, and this fluid is more 
perfectly deprived of its carbon and hydrogen. 

525. The chest is not only most expanded at its lower 
part, but the portion of the lungs that occupies this space of 
the thoracic cavity contains the greater part of the air-cells ; 
and, from the lower two thirds of the lungs the greatest 
amount of carbonic acid is abstracted from the blood, and 
the greatest amount of oxygen gas is conveyed into the cir- 
culating fluid. Hence, contracting the lower ribs is far more 
injurious to the health than diminishing the size of the upper 
part of the chest. 

526. The question is often asked, Can the size of the chest 
and the volume of the lungs be increased, when they have 
been injudiciously compressed, or have inherited this un- 
natural form ? The answer is in the affirmative. The means 
for attaining this end are, a judicious exercise of the lungs, 
by walking in the open air, reading aloud, singing, sitting erect, 
and fully inflating the lungs at each act of inspiration. If the 
exercise be properly managed and persevered in, it will 
expand the chest, and give tone and health to the important 
organs contained in it. But, if the exercise be ill-timed or 
carried to excess, the beneficial results sought will probably 
not be attained. 

Observation. Scholars, and persons who sit much of the 
time, should frequently, during the day, breathe full and 
deep, so that the smallest air-cells may be fully filled with 
air. While exercising the lungs, the shoulders should be 
thrown back and the head held erect. 

527. The movement of the ribs and diaphragm is modified 
by the dress. When the lungs are properly filled with air, 

525. "Why is it more injurious to contract the lower part of the chest than 
the upper ? 526. How can the size of the chest be increased when it is 
contracted ? Give the observation. 527. How is the movement of the 
ribs and diaphragm modified ? 



241 ANATOMY, PHYSIOLOGY, AND HYGIENE. 

the chest is enlarged in every direction. If any article of 
apparel is worn so tight as to prevent the full expansion of 
the chest and abdomen, the lungs, in consequence, do not 
receive air sufficient to purify the blood. The effect of firm, 
unyielding clothing, when worn tight, in preventing a due 
supply of air to the lungs, may be shown by the following 
illustration. 

Illustration. If the diameter of a circle is three feet, the 
circumference will be nine feet. If the diameter is extended 
to four feet, the circumference will be increased to twelve 
feet. Should a tight band be thrown around a circle of nine 
feet, its diameter cannot be increased, for the circumference 
cannot be enlarged. 

528. Any inelastic band, drawn closely around the lower 
part of the chest, or the abdomen, below the ribs, operates 
like the band in the preceding illustration, in restricting the 
movement of the ribs. When any article of dress encircles 
either the chest or abdomen, so as to prevent an increase of 
its circumference, it has an injudicious tendency, as it pre- 
vents the introduction of air in sufficient quantities to purify 
the blood. The question is not, How much restriction 
of the respiratory movements can be endured, and life con- 
tinue ? but, Does any part of the apparel restrict the move- 
ments ? If it does, it is a violation of the organic laws ; and 
though Nature is profuse in her expenditures, yet sooner or 
later, she sums up her account. 

529. In determining whether the apparel is worn too tight, 
inflate the lungs, and, if no pressure is felt, no injurious effects 
need be apprehended from this cause. In testing the tight- 
ness of the dress, some persons will contract to the utmost 
the abdominal muscles, and thus diminish the size of the 

How is the effect of unyielding clothing, when worn tight, illustrated ? 
528. What effect has an inelastic band upon the lower part of the chest ? 
"What question is asked ? 529. How can we determine whether the apparel 
is worn too tight ? 



HYGIENE OF THE RESPIRATORY ORGANS. 245 

chest, by depressing the ribs ; when this is done, the in- 
dividual exclaims, " How loose my dress is ! " This practice 
is both deceptive and ludicrous. A good test is, to put the 
hand on the chest below the arm ; if there is no movement of 
the ribs during respiration, the apparel is too tight. The only 
reliable test, however, is a full inflation of the lungs. 

Observation. Many individuals do not realize the small 
amount of force that will prevent the enlargement of the 
chest. This can be demonstrated by drawing a piece of tape 
tightly around the lower part of the chest of a vigorous adult, 
and confining it with the thumb and finger. Then endeavor 
fully to inflate the lungs, and the movement of the ribs will 
be much restricted. 

530. The position in standing and sitting influences the 
movement of the ribs and diaphragm. When the shoulders 
are thrown back, and when a person stands or sits erect, the 
diaphragm and ribs have more freedom of motion, and the 
abdominal muscles act more efficiently ; thus the lungs have 
broader range of movement than when the shoulders incline 
forward, and the body is stooping. 

531. Habit exercises an influence upon the range of the 
respiratory movements. A person who has been habituated to 
dress loosely, and whose inspirations are full and free, suffers 
more from the tightness of a vest or waistband, than one, the 
range of movements of whose chest has long been subjected 
to tight lacing. 

532. The condition of the brain exercises a great influence 
upon respiration. If the brain is diseased, or the mind 
depressed by grief, tormented by anxiety, or absorbed by 
abstract thought, the contractile energy of the diaphragm and 

Give another test. How can. the amount of pressure necessary to pre- 
vent the enlargement of the chest be demonstrated ? 530. Show the 
effect of position on the movements of the ribs and diaphragm. 531. Show 
the effect of habit on the respiratory movements. 532. State the influence 
of the mind upon respiration. 

21* 



246 ANATOMY, PHYSIOLOGY, AND HYGIENE. 

muscles that elevate the ribs, is much diminished, and the 
lungs are not so fully inflated, as when the mind is influenced 
by joy or other exhilarating emotions. The depressing pas- 
sions likewise lessen the frequency of respiration. By the 
influence of these causes, the blood is but partially purified, 
and the whole system becomes enfeebled. Here we may 
see the admirable harmony between the different parts of 
the body, and the adaptation of all the functions to each 
other. 

533. As the quantity of air inhaled at each unimpeded 
inspiration in lungs of ample size, is about forty cubic inches, 
it follows, if the movement of the ribs and diaphragm is 
restricted by an enfeebled action of the respiratory muscles, 
or by any other means, the blood will not be perfectly purified. 
In the experiment, (§ 522, 523,) suppose forty cubic inches of 
air must pass over the membrane twenty times every minute, 
and that this is the amount required to remove the vapor 
which arises from the membrane ; if only half of this amount 
of air be supplied each minute, only one half as much water 
will be removed from the alcohol through the membrane in 
twenty-four hours ; consequently, the alcohol would be impure 
from the water not being entirely removed. 

534. Restrain the elevation of the ribs and depression of 
the diaphragm, so that the quantity of air conveyed into the 
lungs will be reduced to twenty cubic inches, when forty are 
needed, and the results will be as follows : Only one half of 
the carbonic acid will be eliminated from the system, and the 
blood will receive but one half as much oxygen as it requires. 
This fluid will then be imperfectly oxydated, and partially 
freed of its impurities. The impure blood will be returned 
to the left side of the heart, and the whole system will suffer 
from an infringement of organic laws. 

533. Illustrate the effect upon the blood when the respiratory muscles 
are enfeebled in their action. 534. Show how the blood is imperfectly 
purified by restricting the movements of the ribs and diaphragm. 



HYGIENE OF THE RESPIRATORY ORGANS. 247 

535. Scrofula, or consumption, frequently succeeds a de- 
pressed state of the nervous system. These diseases arise 
from the deposition of tuberculous matter in different parts of 
the body. Those individuals who have met with reverses of 
fortune, in which character and property were lost, afford 
painful examples. Hundreds yearly die from the effect of 
depressed spirits, caused by disappointed hopes, or disap- 
pointed ambition. 

Illustration. A striking instance of the effects of mental 
depression is related by Lsennec. In a female religious 
establishment in France, great austerities were practised ; the 
mind was absorbed in contemplating the terrible truths of 
religion, and in mortifying the flesh. The whole establish- 
ment, in the space of ten years, was several times depopu- 
lated — with the exception of the persons employed at the 
gate, in the kitchen, and garden — with that fatal disease, 
consumption. This institution did not long continue, but was 
suppressed by order of the French government. 

536. The purity of the Hood is influenced by the condition 
of the lungs. When the bronchial tubes and air-cells have 
become partially impervious to air, from pressure upon the 
lungs, from fluids in the chest, from tumors, or from the con- 
solidation of the cells and tubes from disease, — as inflam- 
mation, or the deposition of yellow, cheesy matter, called 
tubercles, — the blood will not be purified, even if the air is 
pure, the lungs voluminous, and the respiratory movements 
unrestricted, as the air cannot permeate the air-cells. 

Observations. 1st. The twenty-three who escaped imme- 
diate death in the Black Hole of Calcutta were soon attacked 
with inflammation of the lungs, by which these organs were 

535. Mention some of the effects of mental depression upon the body. 
What is related by Laennec ? 536. Does the condition of the lungs 
influence the purity of the blood ? Mention some of the conditions that 
•will impede the oxydation of blood in the lungs. What occurred to those 
persons who escaped death in the Black Hole of Calcutta ? 



248 ANATOMY, PHYSIOLOGY, AND HYGIENE. 

consolidated, and thus prevented the permeation of air into 
their cells. This disease of the lungs was caused by breath- 
ing vitiated air. 

2d. One of the precursory symptoms of consumption is the 
feeble murmur of respiration in the upper part of the lungs. 
This condition of these organs is produced by, or frequently 
follows, mental depression, the breathing of impure air, the 
stooping position in standing or sitting, and the restriction of 
the movements of the ribs and diaphragm. 

3d. Persons asphyxiated by carbonic acid, water, stran- 
gling, or any noxious air, after resuscitation, are usually affected 
with coughs and other diseases of the lungs. 

537. Colds and coughs are generally induced by a chill, 
that produces a contraction of the blood-vessels of the skin ; 
and the waste material, which should be carried from the 
body by the agency of the vessels of this membrane, is 
retained in the system, and a great portion of it is returned to 
the mucous membrane of the lungs. For such is the harmony 
established by the Creator, that if the function of any portion 
of the body is deranged, those organs whose offices are similar 
take on an increased action. 

538. The waste material, that should have passed through 
the many outlets of the skin, creates an unusual fulness of 
the minute vessels that nourish the mucous membrane of the 
bronchia ; this induces an irritation of these vessels, which 
increases the flow of blood to the nutrient arteries of the lungs. 
There is, also, a thickening of the lining membrane of the 
lungs, caused by the repletion of the bronchial vessels of the 
mucous membrane ; this impedes the passage of air through 
the small bronchial tubes, and consequently the air-vesicles 

"What is one of the precursory symptoms of consumption ? How is this 
condition frequently produced ? What diseases usually follow asphyxia by 
carbonic acid, water, strangling, &c. ? 537. How are colds generally in- 
duced ? 538. What effect has a common cold upon the mucous membrane 
of the lungs ? 



HYGIENE OF THE RESPIRATORY ORGANS. 249 

cannot impart a sufficient quantity of oxygen to purify the 
blood, and this fluid, imperfectly purified, does not pass with 
facility through the lungs. An additional obstacle to the free 
passage of air into the lungs, is the accumulation of blood in 
the pulmonary vessels. 

539. As colds and coughs are very generally treated by the 
" matrons " of the community, or by the patient, the following 
suggestions may aid in directing a proper treatment : To 
effect a speedy cure, it is necessary to diminish the amount of 
fluid in the vessels of the lungs. This can be effected in two 
ways : 1st. By diminishing the quantity of blood in the sys- 
tem ; 2d. By diverting it from the lungs to the skin. The 
first condition can be easily and safely affected, by abstaining 
from food, and drinking no more than a gill of fluid in twenty- 
four hours. As there is a continuous waste from the skin 
and other organs of the system, the quantity of blood by this 
procedure will be diminished, and the lungs relieved of the 
accumulated fluid. 

540. The second condition can be accomplished by resort- 
ing to the warm or vapor bath. These and the common 
sweats will invite the blood from the lungs to the skin. By 
keeping up the action of the skin for a few hours, the lungs 
will be relieved. In some instances, emetics and cathartics 
are necessary ; mucilages, as gum arabic or slippery-elm 
bark, would be good. After the system is relieved, the skin 
is more impressible to cold, and consequently requires care- 
ful protection by clothing. In good constitutions, the first 
method is preferable, and generally sufficient without any 
medicine or " sweating." 

541. The method of resuscitating persons apparently 
drowned. In the first instance, it is necessary to press the 
chest, suddenly and forcibly, downward and backward, and 

539. Give the first method for the treatment of cold. 540. The second 
method. 541,542. How should persons apparently drowned be treated? 



250 ANATOMY, PHYSIOLOGY, AND HYGIENE. 

instantly discontinue the pressure. Repeat this without inter- 
mission, until a pair of bellows can be procured. When the 
bellows are obtained, introduce the nozzle well upon the base 
of the tongue, and surround the mouth and nose with a towel 
or handkerchief, to close them. Let another person press 
upon the projecting part of the neck, called " Adam's apple," 
while air is introduced into the lungs through the bellows. 
Then press upon the chest, to force the air from the lungs, to 
imitate natural breathing. 

542. Continue the use of the bellows, and forcing the air 
out of the chest, for an hour at least, unless signs of natural 
breathing come on. Wrap the body in warm, dry blankets, 
and place it near the fire, to preserve the natural warmth, as 
well as to impart artificial heat. Every thing, however, is 
secondary to filling the lungs with air. Avoid all friction 
until breathing is restored. Send immediately for medical aid. 

543. The means of resuscitating persons asphyxiated from 
electricity, 8fc. In apparent death from electricity, (light- 
ning,) the person is frequently asphyxiated from pa-ral'y-sis 
(palsy) of the respiratory muscles. To recover such persons, 
resort to artificial respiration. In cases of apparent death 
from hanging or strangling, the knot should be untied or cut 
immediately ; then use artificial respiration, or breathing, as 
directed in apparent death from drowning. 

Observation. It is an impression, in many sections of the 
country, that the law will not allow the removal of the cord 
from the neck of a body found suspended, unless the coroner 
be present. It is therefore proper to say, that no such delay 
is necessary, and that no time should be lost in attempting 
to resuscitate the strangled person. 

544. The method of resuscitating persons apparently dead 
from inhaling carbonic acid gas. When life is apparently 

543. "What treatment should be adopted in asphyxia from electricity ? 
From hanging ? 544. What should be the treatment in asphyxia from 
inhaling carbonic acid gas ? 



HYGIENE OF THE RESPIRATORY ORGANS. 251 

extinct from breathing carbonic acid gas, the person should 
be carried into the open air. The head and shoulders should 
be slightly elevated ; the face and chest should be sponged or 
sprinkled with cold water, or cold vinegar and water, while the 
limbs are wrapped in dry, warm blankets. In this, as in 
asphyxia from other causes, immediately resort to artificial 
respiration. 

Observations. 1st. Many persons have died from breathing 
carbonic acid that was formed by burning charcoal in an open 
pan or portable furnace, for the purpose of warming their 
sleeping-rooms. This is not only produced by burning char- 
coal, but is evolved from the live coals of a wood fire ; and 
being heavier than air, it settles on the floor of the room ; and, 
if there is no open door or chimney-draught, it will accumu- 
late, and, rising above the head of an individual, will cause 
asphyxia or death. 

2d. In resuscitating persons apparently dead from causes 
already mentioned, if a pair of bellows cannot be procured 
immediately, let their lungs be inflated by air expelled from 
the lungs of some person present. To have the expired air 
as pure as possible, the person should quickly inflate his 
lungs, and instantly expel the air into those of the asphyxiated 
person. Place the patient in pure air, admit attendants 
only into the apartment, and send for a physician without 
delay. 

"What sad results frequently follow the burning of charcoal in a close 
room ? What suggestion in resuscitating asphyxiated persons ? 



252 ANATOMY, PHYSIOLOGY, AND HYGIENE. 



CHAPTER XXVII. 

ANIMAL HEAT. 

545. The true sources of animal heat, or calorification, are 
still imperfectly known. No hypothesis has, as yet, received 
the concurrent assent of physiologists. We see certain phe- 
nomena, but the ultimate causes are hidden from our view. 
Its regular production, to a certain degree, is essential both 
to animal and vegetable life. 

546. There is a tendency between bodies of different tem- 
perature to an equilibrium of heat. Thus, if we touch or 
approach a hot body, the heat, or caloric passes from that 
body to our organs of feeling, and gives the sensation of heat. 
On the contrary, when we touch a cold body, the heat passes 
from the hand to that body, and causes a sensation of cold. 

547. The greater number of animals appear cold when 
we touch them ; and, indeed, the temperature of their bodies 
is not much above that of the atmosphere, and changes with 
it. In man, and other animals that approach him in their 
organization, it is otherwise. They have the faculty of pro- 
ducing a sufficient quantity of caloric to maintain their tem- 
peratures nearly at the same degree, under all atmospheric 
changes, and keep themselves warm. 

548. Those animals whose proper heat is not very per- 
ceivable, are called cold-blooded ; as most species of fishes, 
toads, snakes, turtles, and reptiles generally. Those animals 

545 — 570. What is said respecting animal heat? 545. Are the true sources 
of animal heat known ? What do we see ? 546. What is the tendency 
between bodies of different temperatures ? Give an explanation. 547. What 
is said of the temperature of animals ? 548. What is meant by cold-blooded 
animals ? By warm-blooded animals ? 



ANIMAL HEAT. 253 

which produce sufficient heat independently of the atmosphere 
surrounding them, are called warm-blooded ; as man, birds, 
quadrupeds, &c. 

549. The temperature of man is about 98°, (Fahrenheit's 
thermometer,) and that of some other animals is higher ; the 
temperature of birds, for example, is about 110°. It is ob- 
vious, that in most parts of the globe, the heat of the atmos- 
phere is, even in summer, less than that of the human body. 
In our latitude, the mercury rarely attains 98°, and sometimes 
it descends to several degrees below zero. 

550. Captain Parry, with his ship's company, in his voyage 
of discovery to the arctic regions, wintered in a climate where 
the mercury was at 40°, and sometimes at 55° below zero. 
Captain Back found it 70° below zero. These were 72° and 
102° below the freezing point, or about 200° below that of 
their own bodies, and still they were able to resist this low 
temperature, and escape being " frost-bitten." 

551. Captain Lyon, who accompanied Captain Parry in his 
second voyage to the northern regions, found the tempera- 
ture of an arctic fox to be 106°, while that of the atmosphere 
was 32° below zero ; making a difference between the tem- 
perature of the fox and that of the atmosphere, of 138°. Cap- 
tain Scoresby found the temperature of a whale, in the Arctic 
Ocean, to be 104°, or nearly as high as that of other animals 
of the same kind in the region of the equator, while the tem- 
perature of the ice was as low as 32°, and the water was 
nearly as cold. These facts show what a strong counteract- 
ing energy there is in animals against the effects of cold. 

552. On the other hand, it has been ascertained by numer- 
ous and well-conducted experiments, that the human body can 

549. What is the temperature of the human body ? Of birds ? How 
does the heat of the atmosphere in summer, in our latitude, compare with 
that of the human system ? 550. What is related of Captain Parry ? Of 
Captain Back ? 551. Of Captain Lyon ? Of Captain Scoresby ? What do 
these facts show ? 552. What has been ascertained on the other hand ? 
22 



254 ANATOMY, PHYSIOLOGY, AND HYGIENE. 

be exposed, even for a length of time, to a very high tem- 
perature, without essentially elevating that of the body. Chan- 
trey, the sculptor, often entered the furnace, heated for drying 
his moulds, when the temperature indicated by the thermom- 
eter was 330°. Chaubert, the Fire-King, is said to have 
entered ovens when heated to 600°. In 1774, Sir Charles 
Blagden entered a room in which the mercury rose to 260°. 
He remained eight minutes without suffering. 

553. In order to render it certain that there was no fallacy, 
says Sir Charles Blagden, " in the degree of heat shown by 
the thermometer, but that the air breathed was capable of 
producing all the well-known effects of such a heat on inan- 
imate matter, I put some eggs and beefsteak upon a tin frame 
placed near the thermometer, and farther distant from the 
cockle than from the wall of the room. In about twenty min- 
utes the eggs were taken out, roasted quite hard ; and in forty- 
seven minutes, the steak was not only dressed, but almost 
dry." 

554. If a thermometer be placed under the tongue of a 
healthy person, in all climates and seasons the temperature 
will be found nearly the same. Sir Charles Blagden, " while 
in the heated room, breathed on a thermometer, and the 
mercury sank several degrees ; and when he expired forcibly, 
the air felt cool as it passed through the nostrils, though it was 
scorching hot when it entered them in inspiration." 

Observation. Did not the human body possess within itself 
the power of generating and removing heat, so as to maintain 
nearly an equality of temperature, the most fatal consequences 
would ensue. In northern latitudes, especially, in severe 
weather of winter, the blood would be converted into a solid 



What is related of Chantrey ? Of Chaubert ? Of Sir Charles Blagden ? 
553. Give Sir Charles's own statement. 554. What is said of the tem- 
perature of the human tongue ? Mention the experiment by Sir Charley 
Blagden. What would be the effect if the human system did not main- 
tain an equality of temperature ? 



ANIMAL HEAT. 255 

mass ; and on the other hand, the fatty secretion, when sub- 
jected to equatorial heat, would become fluid, and life would 
be extinguished. 

555. To enable man, and other warm-blooded animals, to 
maintain this equilibrium of temperature under such extremes 
of heat and cold, naturally suggests two inquiries : 1st. By 
what organs is animal heat generated ? 2d. By what means 
is its uniformity maintained ? 

556. The ancients had no well-arranged theory on the sub- 
ject of animal heat. They believed that the chief object of 
respiration was to cool the blood, and that the heart was the 
great furnace where all the heat was generated. At a later 
period, Mayow, from his discoveries respecting respiration, 
asserted that the object of respiration was to produce heat, 
and denied that the blood was cooled in the lungs. 

557. When it was discovered that, both in combustion and 
respiration, carbonic acid was produced and oxygen absorbed, 
it led Dr.. Black to conclude that breathing was a kind of 
combustion by which all the heat of the body was produced. 
This theory was objected to, because, if all the heat was gen- 
erated in the lungs, like those parts of a stove in contact 
with the fuel, they would be at a higher temperature than those 
parts at a distance, which was known not to exist. 

558. The next theory, and one which received the sanction 
of the scientific men of Europe, was proposed by Dr. Craw- 
ford. He agreed with Dr. Black that heat not only was 
generated in the lungs, but that the arterial blood had a greater 
capacity for heat than the venous-, and that this increase of 
capacity takes place in the lungs. At the moment heat is 
generated, a portion of it, under the name of latent heat, is 
absorbed and conveyed to the different parts of the body. 

555. What inquiries are naturally suggested ? 556. What was the theo- 
ry of the ancients ? What did Mayow assert at a later period ? 557. What 
was the theory of Dr. Black ? The objection ? 558. What was the theory 
of Dr. Crawford ? 



256 ANATOMY, PHYSIOLOGY, AND HYGIENE. 

Wherever arterial blood is converted into venous, this latent 
heat is given out. But, unfortunately for this theory, Dr. Davy 
proved the capacity of both, for heat, to be nearly the same. 

559. No one can doubt that, respiration and animal heat 
are closely connected. Those animals whose respiratory 
apparatus is the most extended, have the highest temperature. 
An example is seen in birds, whose organs of respiration 
extend over a large part of the body, and their temperature 
is 12° above man ; while the respiratory apparatus of cold- 
blooded animals, as some kinds of fish, is imperfect, and only 
a small quantity of blood is subjected, at any time, to the 
effects of respiration. 

560. To understand the process by which heat is generated 
in the human system and in animals, it will be necessary to 
state : 1st. That the apparent heat of a body, as perceived 
by the touch, or as indicated by a thermometer, is not the 
measurement of heat contained in the body, or its capacity 
for heat. 

Illustration. If we mix one pound of water, at the tempera- 
ture of 60°, with another pound at 91°, the resulting tempera- 
ture will be exactly the medium, or 75^-°. But, if we mix a 
pound of water at 60° with a pound of quicksilver at 91°, the 
resulting temperature will be only 61°, because the capacity 
of water for heat is so much greater than that of quicksilver, 
that the heat which raised the quicksilver 31° will raise the 
water only 1°. 

561. 2d. When the density and the arrangement of the 
atoms of a body are changed, its capacity to hold heat in a 
latent state is altered. If it will retain more, heat will be 
absorbed from contiguous and surrounding substances ; but, 

The objection ? 559. In what do all the physiologists of the present day 
concur ? How is it proved that respiration and animal heat are closely con- 
nected ? 560. What is said of the apparent heat of bodies ? How is this 
illustrated ? 561. What is the effect when the density and the arrange- 
ment of the atoms of a body are changed ? 



ANIMAL HEAT. 257 

if its capacity for caloric is lessened, heat will be set free and 
given out to surrounding bodies. 

Illustrations. 1st. Ice and salt, (muriate of soda,) when 
mixed, are converted into a fluid. In this state they will hold 
more heat than when solid. The heat necessary to produce 
this change is drawn from the surrounding medium, which is 
made proportionally colder by the loss of caloric imparted to 
the ice and salt. It is by this chemical process that " ice- 
cream " is made. 

2d. On the other hand, mix water and sulphuric acid, (oil 
of vitriol,) of the temperature of 60°, and the mixture will 
become quite warm, and will freely impart its heat to sur- 
rounding and contiguous objects. 

562. The same principle is exhibited, when oxygen 
unites with an inflammable body, as in the burning of wood, 
coal, oil, &c. In combustion, the oxygen of the atmosphere 
unites with carbon and hydrogen, and carbonic acid and 
water are produced This process, according to all the known 
laws of caloric, is attended with heat. The quantity of heat 
disengaged in combustion is always in proportion to the 
amount of carbon and hydrogen consumed ; thus a piece of 
wood weighing one pound, in burning slowly, would give out 
the same quantity of heat as a pound of shavings of the 
same wood, in burning rapidly. Upon these principles, the 
production of animal heat may be understood. 

563. The food contains carbon and hydrogen. These 
exist in the chyle. The old and waste atoms of the body 
likewise contain the same elements. In the lungs the oxygen 
and nitrogen of the inspired air are separated. It is now 
supposed that the oxygen enters the capillary vessels of the 

Give the 1st illustration. The 2d. 562. What changes take place when 
oxygen unites with an inflammable body ? To what is the quantity of heat 
proportionate in combustion ? Give an example. 563. How are carbon 
and hydrogen supplied to the system ? How the oxygen ? Where does 
the oxygen mingle with the blood ? 

22* 



258 ANATOMY, PHYSIOLOGY, AND HYGIENE. 

lungs, and mingles with the blood, with which it is carried to 
the heart and thence to the nutrient capillary vessels of every 
part of the system. 

564. In the capillary vessels, the oxygen of the arterial 
blood unites with the carbon and hydrogen which the refuse 
materials contain, and carbonic acid and water are formed. 
The combustion of carbon and hydrogen in the capillaries of 
every part of the system, (the lungs not excepted,) is attended 
with a disengagement of heat, and the carbonic acid and 
water are returned to the lungs in the dark-colored blood, 
and evolved from the system. 

565. Sir Benjamin Brodie and some others have main- 
tained, that the heat of the system is generated exclusively 
by the influence of the brain and nerves. This theory is dis- 
carded by most physiologists ; yet it is true that the nervous 
system exercises a great influence over the action of the 
capillary vessels in the process of nutrition, secretion, and 
absorption. When these operations are most active, the 
change among the particles of matter of which the body is 
composed, is .then greatest, and the generation of heat is 
increased in a corresponding degree. 

566. The necessity of pure, red blood in the production of 
animal heat, is shown when the vessels that carry blood to a 
limb are ligated, or tied ; the part immediately becomes 
colder. The necessity of nervous influence is seen in the 
diminished temperature of a paralytic limb. 

567. Our next inquiry is, By what means is the uniformity 
of temperature in the body maintained ? As there is a con- 
stant generation of heat in the system, there would be an 
undue accumulation, — so much so as to cause disagreeable 

564. Where does it unite with the carbon and hydrogen contained in the 
body, and how is heat generated ? 565. What was the theory of Sir Ben- 
jamin Brodie ? Is this theory in general discarded ? What is true of this 
theory ? 566. How is the necessity of pure, red blood and nervous action 
shown in the production of animal heat ? 



ANIMAL HEAT. 259 

sensations, — if there were no means by which it could be 
evolved from the body, or its production lessened. 

568. It has been ascertained that the principal means by 
which the system is kept at a uniform temperature, is the 
immense evaporation from the skin and lungs. These mem- 
branes, in an ordinaiy state, are constantly giving out water, 
which is converted into vapor, and carried off by the surround- 
ing air. The quantity of heat abstracted from the system to 
effect this, depends on the rapidity of the change of air, its 
temperature, and the amount of water it contains in a state 
of vapor. The quantity removed is greatest when the air 
is warm and dry, and the change, or current, rapid. 

Observations. 1st. The first discovery of the use of free 
evaporation of the perspiration from the skin in reducing the 
heat of the body, and the analogy subsisting between'this 
process and that of the evaporation of water from a rough 
porous surface, so constantly resorted to in warm countries, 
as an efficacious means of reducing the temperature of the air 
in rooms, and of wine and other drinks, much below that of 
the surrounding atmosphere, was made by Franklin. 

2d. In all ages and climes, it has been observed that the in- 
creased temperature of the skin and system in fevers, is abated 
as soon as free perspiration is restored. In damp, close weath- 
er, as during the sultry days of August, although the tempera- 
ture is lower, we feel a disagreeable sensation of heat, because 
the saturation of the air with moisture lessens evaporation, and 
thus prevents the escape of heat through the lungs and skin. 

3d. It is on the principle of the evaporation of fluids, that 
warm vinegar and water, applied to the burning, aching head, 
cools it, and imparts to it a comfortable feeling. The same 

568. What are the principal means by which a uniform temperature of the 
body is maintained ? On what does the quantity of heat abstracted from 
the system depend? What discovery relative to animal heat is due to 
Franklin ? What is said of free perspiration in fevers ? What occasions 
the disagreeable sensation of heat in damp, close weather ? 



260 ANATOMY, PHYSIOLOGY, AND HYGIENE. 

results follow if warm liquids are applied to the skin in the 
hot stage of fever ; and this evaporation can be increased by- 
constant fanning. 

4th. It is frequently noticed, in very warm weather, that 
dogs and other domestic animals are seen with their tongues 
out of their mouths, and covered with frothy secretions. This 
is merely another mode of reducing animal heat, as the 
skin of such animals does not perspire as much as that of 
man. 

569. Under some circumstances, a portion of the heat of 
the system is removed by radiation. When cold air comes in 
contact with the skin and mucous membrane of the lungs, 
heat is radiated from the body, as from a stove,- to restore an 
equilibrium of temperature. The radiation of heat from the 
bod^ is greatest when we are in a current of cold air, or 
when a brisk, cold wind is blowing upon us. 

570. As the primary object of the different processes of 
nutrition is to supply animal heat, so the action of the dif- 
ferent nutritive organs is modified by the demands of the 
system for heat. When heat is rapidly removed from the 
body, the functional activity of the organs of nutrition is 
increased. When the system is warmed by foreign influence, 
the activity of the nutritive organs is diminished. This leads 
to the natural, and, we may add, instinctive change in the 
quality and quantity of food at different seasons of the year. 

569. When is heat radiated from, the body ? "When is it greatest ? 
570. "What is the primary object of the different processes of nutrition ? 
"When is the activity of the nutritive organs increased ? When diminished ? 
To what does this lead ? 



HYGIENE OF ANIMAL HEAT. 261 



CHAPTER XXVIII. 

HYGIENE OF ANIMAL HEAT. 

571. The amount of heat generated in man and inferior 
animals depends upon the quantity and quality of the food, 
age, exercise, the amount and character of the respired air, 
condition of the brain, skin, and general system. 

572. Animal heat is modified by the proportion of digest- 
ible carbon which the food contains, and by the quantity con- 
sumed. As the kind of fuel that contains the greatest amount 
of combustible material evolves the most caloric when burned, 
so those articles of food that contain the greatest quantity of 
carbon produce the most heat when converted into blood. 
The inhabitants of the frigid zones, and individuals in 
temperate climates during the cold season, consume with 
impunity stimulating animal food, that contains a large 
proportion of carbon, while the inhabitants of the tropical 
regions, and persons in temperate climates during the warm 
season, are more healthy with a less stimulating or vegetable 
diet. 

Observation. When we ride or labor in cold weather, an 
adequate amount of nutritious food will sustain the warmth of 
the system better than intoxicating drinks. 

573. Age is another influence that modifies the generation 
of animal heat. The vital forces of the child being feeble, 
less heat is generated in its system than in that of an adult. 

571 — 585. Give the hygiene of animal heat. 571. State some of the influ- 
ences that modify the generation of animal heat. 572. What element of 
the food influences the generation of heat ? "When and where can animal 
food be eaten with impunity ? Give the practical observation. 



262 ANATOMY, PHYSIOLOGY, AND HYGIENE. 

The experiments of Dr. Milne Edwards show that the power 
of producing heat in warm-blooded animals, is at its minimum 
at birth, and increases successively to adult age ; and that 
young children part with their heat more readily than adults, 
and, instead of being warmer, are generally a degree or two 
colder. After adult age, as the vital powers decline, the 
generation of heat is diminished, as the energies of the sys- 
tem are lessened. Hence the young child, and the debili- 
tated aged person, need more clothing than the vigorous 
individual of middle age. 

574. Exercise is an influence that modifies the generation 
of animal heat. As carbon and hydrogen enter into the com- 
position of the organs of the body, whatever increases the 
flow of blood in the system, increases also the deposition of 
new material, and the removal of the waste particles. This 
change among the particles of matter is attended with an 
elevation of temperature, from the union of oxygen with the 
carbon and hydrogen of the waste atoms. For this reason, a 
person in action is warmer than in a quiescent state. Conse- 
quently, the amount of clothing should be increased, when 
exercise or labor is diminished or suspended. 

575. On the other hand, whatever impedes the circula- 
tion and the interchange of the atoms of matter, diminishes 
animal heat. Common observation shows, that the extremities 
are not as warm when tight gloves or boots are worn as 
when they are loose. One reason is, the circulation of blood 
is impeded, which is attended with less frequent change of the 
particles of matter. 

576. The quantity of air which is inhaled modifies the heat 
of the system. In the generation of heat in a stove, air, 
or oxygen, is as essential as the wood or coal. It is equally 

"What do the experiments of Dr. Milne Edwards show ? 574. Why 
does exercise influence animal heat ? 575. What is the effect when the 
circulation of blood is impeded? Give examples. 576. Why do those 
persons that have broad chests and voluminous lungs suffer less from 
cold than the narrow-chested with small lungs ? 



HYGIENE OF ANIMAL HEAT. 263 

so in the production of animal heat. The oxygen of the 
inspired air should be in proportion to the carbon and hydro 
gen to be consumed. This requires voluminous lungs, 
together with free movements of the ribs and diaphragm. 
A person whose chest is small, and whose apparel is worn 
tight over the ribs, suffers more from the cold, and complains 
more frequently of chilliness and cold extremities, than the 
broad-chested and loosely dressed. 

Observation. Fishes that breathe by means of gills, as the 
cod, pike, &c, depend solely on the small quantity of oxygen 
that is contained in the air mixed with the water. Their 
temperature is not much greater than the medium in which 
they live. Whales, dolphins, &e., breathe by means of lungs ; 
and the inhalation of atmospheric air makes their temperature 
about 100°, independent of the heat of the element in which 
they live. 

577. The quality of respired air influences the generation 
of animal heat. In vestries, and other public rooms, when 
crowded with an audience, where the ventilation is inadequate, 
the lamps will emit but a faint light, because the oxygen is 
soon expended, and there is not enough of the vivifying prin- 
ciple to unite with the oil and disengage light. In the human 
body, when the respired air has lost some of its life-giving 
properties, the combustion that takes place in different parts 
of the system is not so complete as when it contains a proper 
proportion of oxygen ; and hence less heat is disengaged. 
For this reason, those persons that breathe impure air, either 
in the daytime or night, require more clothing, than those 
that work and sleep in well- ventilated rooms. 

578. The condition of the brain and nervous system affects 



What is said of those fishes that breathe by means of gills ? Of those 
that breathe by means of lungs ? 577. Why do lamps give but a faint 
light in crowded, unventilated rooms ? What effect on animal heat has 
impure air ? 578. Mention the effects of some of the mental emotions on 
animal heat. 



264 ANATOMY, PHYSIOLOGY, AND HYGIENE. 

the generation of animal heat. If the brain is diseased, or 
the mind is absorbed in thought, depressed by sorrow, or 
aroused from fear, the breathing becomes slow and scarcely 
perceptible, and a chilliness pervades the body, particularly 
the extremities ; while, on the contrary, if the mind and ner- 
vous system are excited by joyous and agreeable emotions, 
the circulation of blood is quicker, and the system more pow- 
erfully resists external cold. During sleep, when the brain 
is partially inactive, less heat is generated than when awake. 
Observation. The preceding remark explains why an indi- 
vidual who sleeps in the same clothing that was adequate to 
prevent chills while awake, contracts a cold, unless he throws 
over him an additional covering. 

579. The state of the skin exercises much influence in the 
generation of heat. If the functions of this membrane are 
not interrupted, more heat will be generated than when it is 
pallid and inactive. The action of the capillaries is most 
energetic when the skin is clean ; on this account, before 
taking a walk or a ride, in cold weather, remove all impurities 
from the skin, by thorough ablution and vigorous friction. 

580. The amount and kind of clothing modify the tem- 
perature of the system. Those persons that are well clothed 
have greater power to resist cold than the thinly apparelled, 
because both the evaporation and the radiation from the skin 
are impeded, and less heat, in consequence, is abstracted from 
the body. If the articles of apparel possess the property of 
retaining air in their meshes, as flannel, the removal of heat 
is not as rapid as when linen is worn. 

Observation. In winter, although more heat is generated in 
the system than in summer, yet we require more clothing, 



What does the preceding remark explain ? 579. What suggestion 
respecting the condition of the skin before taking a walk or ride in a cold 
day ? Why ? 580. Do the amount and kind of clothing affect animal 
heat ? What is said of well-clothed persons ? When does the system 
generate the most heat ? 



HYGIENE OF ANIMAL HEAT. 265 

and also those articles that are poor conductors of heat, because 
caloric is more rapidly extracted in clear, cold weather, than 
in a warm day. 

581. The health and constitution influence the generation 
of heat. When the health is firm, and the constitution vigor- 
ous, less clothing is needed, for the change among the par- 
ticles of matter is more rapid, and more heat is generated, 
than when the opposite condition obtains. Persons of a fee- 
ble constitution, particularly, if any of the vital organs* are 
diseased, need more clothing and require rooms of a warmer 
temperature, than individuals who are free from disease and 
have a vigorous constitution. 

Observation. Persons who are infirm, and whose vital 
powers are feeble, in general, accustom themselves to an 
undue amount of clothing and warm rooms. A more judi- 
cious practice would be, to exercise more and use a moderate 
amount of clothing, together with a more nutritious diet. 

582. The surplus heat should be removed equally from all 
parts of the system. The rapid evaporation of fluids, as in 
free perspiration, or from radiation, as in a cold atmosphere, 
is attended with a removal of heat from the system. This 
modifies the action of the circulatory vessels. Consequently, 
if heat is suddenly and rapidly abstracted from one part of 
the system, the equilibrium of the circulation is destroyed, 
which will produce disease. 

Observation. Currents of air that impinge upon small 
portions of the body, as from small apertures, or from a 



* The brain, lungs, heart, and digestive organs, are called vital organs. 

Why do we, then, require more clothing in winter than in summer ? 
581. Why do persons of firm health and vigorous constitutions need less 
clothing than those who are feeble ? What is a general practice among 
infirm persons ? What would be more judicious ? 582. Why should the 
surplus heat be removed equally from all parts of the system ? What is 
said respecting currents of air from small apertures ? 
23 



266 ANATOMY, PHYSIOLOGY, AND HYGIENE. 

window slightly raised, should be avoided. They are more 
dangerous than to expose the whole person to a brisk wind, 
because the current of air removes the heat from the part 
exposed, which disturbs the circulation of blood and causes 
disease, usually in the form of " colds." For the same 
reason, it is not judicious to stand in an open door, or the 
opening of a street. 

583. The system suffers less when the change of tempera- 
ture is gradual. The change in the production of heat, as 
well as in the evaporation of fluids from the system, is gradual 
when not influenced by foreign causes. This gradual change 
is known under the name acclimation. By this means the 
body is enabled to endure tropical heat and polar cold. 
Owing to this gradual adaptation of the system to different 
temperatures, we can bear a greater degree of heat in the 
summer between the tropics, than in the winter under the 
polar circles. On the other hand, we can endure a greater 
degree of cold in winter and in the arctic region, than in 
the summer and in equatorial countries. 

584. The sensation of heat which would be oppressive in 
a mild, warm day of January, would only be grateful in July, 
and a degree of cold which could scarcely be endured in 
August, would not be uncomfortable in December. The 
changes of season in our latitude prevent the disagreeable and 
perhaps fatal consequence that would follow, if no spring or 
autumn intervened between the severity of winter's cold and 
the intensity of summer's heat. During the transition periods, 
the constitution is gradually changed, and adapted to bear the 
extremes of temperature without suffering. The amount of 

583. In what manner should change of temperature take place, to he 
adapted to the body ? How is the body enabled to endure tropical heat 
and polar cold ? State some of the effects of the gradual adaptation of the 
system to different temperatures. 584. What is said relative to a warm day 
in winter ? To a cold day in summer ? What is said of the changes of 
seasons in our latitude ? What effect on the constitution during spring 
and autumn ? What change in the amount of heat generated ? 



HYGIENE OF ANIMAL HEAT. 267 

heat generated in the nutrient capillary vessels, is likewise 
diminished or increased as the temperature of the season 
becomes greater or less. 

585. But, on the contrary, we cannot suddenly pass from 
one extreme of temperature to the other with impunity. Let 
an inhabitant of Quebec suddenly arrive in Cuba in February, 
and he would suffer from languor and exhaustion ; after be- 
coming acclimated to this tropical climate, let him suddenly 
return to Quebec in January, and the severity of the weather 
would be almost insupportable. 

Observations. 1st. Experience shows that heated rooms, as 
well as tropical climates, lessen the generation of heat in the 
body, and likewise the power of resisting cold. It would be 
idle for the merchant from his warehouse, or the mechanic 
from his heated shop, to attempt to sit on the box with a 
coachman, with the same amount of clothing as his compan- 
ion, who is daily exposed to the inclemency of the weather. 

2d. " It is the power of endurance of cold at one period, 
and the absence of its necessity at another, that enables ani- 
mals, in their wild and unprotected state, to bear the vicissi- 
tudes of the seasons with so little preparation in clothing, and 
so little real inconvenience.'" 



585. What effect on the system has a sudden transition from a cold to a 
warm climate ? What does experience show ? Why do wild animals bear 
the vicissitudes of the seasons with so little preparation in clothing ? 



268 ANATOMY, PHYSIOLOGY, AND HYGIENE. 

CHAPTER XXIX. 

THE VOICE. 

586. The beautiful mechanism of the vocal instrument, 
which produces every variety of sound, from a harsh, unme- 
lodious tone, to a soft, sweet, flute-like sound, has, as yet, been 
imperfectly imitated by art. It has been compared, by many 
physiologists, to a wind, reed, and stringed instrument. This 
inimitable, yet simple instrument, is the Lar'ynx. 

587. Incidentally, the different parts of the respiratory 
organs, as well as the larynx, are subservient to speaking and 
singing. The tongue, nasal passages, muscles of the fauces 
and face, are agents which aid in the intonation of the voice. 

ANATOMY OF THE VOCAL ORGANS. 

588. The larynx is a kind of cartilaginous tube, which, 
taken as a whole, has the general form of a hollow, reversed 
cone, with its base upward toward the tongue, in the shape of 
an expanded triangle. It opens into the pharynx, at its 
superior extremity, and communicates, by its inferior opening, 
with the trachea. It is formed by the union of five cartilages, 
namely, the Thy'roid, the Cri'coid, the two A-ryt-e'noid, and 
the Ep-i-glot'tis. These are bound together by ligaments, 
and moved by muscles. 



586. What is said of the structure of the vocal instrument ? "With what 
instrument have physiologists compared it ? What is the vocal instrument 
called ? 587. What organs are called into action in speaking beside the 
larynx ? 588 — 596. Give the anatomy of the vocal organs. 588. Describe 
the larynx. Name the cartilages that form the larynx. 



ANATOMY OF THE VOCAL ORGANS. 



269 



589. The thyroid cartilage is the largest of the five, 
and forms the prominence in the front of the neck, called 
Po'mum A-da'mi, (Adam's apple.) It is composed of two 
parts, and is connected with the bone of the tongue above, 
and with the cricoid cartilage below. 

590. The cricoid cartilage takes its name from its resem- 
blance to a ring. It is situated below the thyroid cartilage ; 
it is narrow in front, broader at the sides, and still broader 
behind, where it is connected with the thyroid cartilage. 
Below, it connects with the first ring of the trachea. 



Fig. 102. 



Fig. 103. 





Fig. 102. Aside view of the cartilages of the larynx. * The front side of the thy- 
roid cartilage. 1, The os hyoides, (bone at the base of the tongue.) 2, The liga- 
ment that connects the hyoid bone and thyroid cartilage. 3, 4, 5, The thyroid car- 
tilage. 6. The cricoid cartilage. 7, The trachea. 

Fig. 103. A posterior view of the cartilages and ligaments of the larynx. 1, The 
posterior face of the epiglottis. 3, 3, The os hyoides. 4, 4, The lateral ligaments 
which connect the os hyoides and thyroid cartilage. 5, 5, The posterior face of the 
thyroid cartilage. 6, 6, The arytenoid cartilages. 7, The cricoid cartilage. 8, 8, 
The junction of the cricoid and the arytenoid cartilages. 12. The first ring of the 
trachea. 



589. Describe the thyroid cartilage. 590. From what does the cricoid 
cartilage derive its name ? "Where is it situated ? Explain fig. 102. 
Fig. 103. 

23* 



270 



ANATOMY, PHYSIOLOGY, AND HYGIENE. 



591. The arytenoid cartilages are small triangular 
bodies placed upon the back part of the cricoid cartilage. 
They are connected with the thyroid cartilages, by four 
ligaments, called Vo'cal Cords. 

592. The epiglottis is fibro-cartilaginous, and is placed 
behind the base of the tongue. In shape it resembles a leaf 
of parsley. 

593. The vocal cords, or ligaments, are formed of elastic 
and parallel fibres, enclosed in a fold of mucous membrane. 
They are about two lines in width, and pass from the anterior 
angle of the thyroid cartilage, to the two arytenoid cartilages. 



Fig. 104. 



Fig. 105. 





Fig. 104. An ideal, lateral section of the larynx. 1, 1, The upper vocal cords. 
2, 2, The lower vocal cords. 3, 3, The glottis. 4, 4, The ventricles of the larynx. 

Fig. 105. A vertical section of the larynx. 2, The os hyoides. 4, The apex of 
the epiglottis. 7, The superior vocal ligament. 9, The ventricle of the larynx. 
10. The lower vocal ligament. 11, The arytenoid cartilage. 12, 13, The cricoid 
cartilage. 14, The trachea. 18, The oesophagus. 



591. Describe the arytenoid cartilages. 592. "What is said of the epi- 
glottis ? 593. Give the structure of the vocal cords. Where is the ventri- 
cle of the larynx. ? Where is the glottis situated ? What is represented 
by fig. 104 ? Explain fig. 105. 



ANATOMY OF THE VOCAL ORGANS. 271 

The one is called the superior, and the other the inferior vocal 
ligament. The cavity, or depression between the superior 
and inferior ligament, is called the ventricle of the larynx. 
The aperture, or opening between these ligaments, is called 
the glottis, or chink of the glottis. It is about three fourths 
of an inch in length, and one fourth of an inch in width, the 
opening being widest at the posterior part. This opening is 
enlarged and contracted by the agency of the muscles appro- 
priated to the larynx. 

Fig. 106. 




Fig. 106. A view of the larynx from above, showing the vocal ligaments. 1, The 
anterior edge of the larynx. 4, The posterior face of the thyroid cartilage. 5, 5, The 
arytenoid cartilages. 6, 6, The vocal ligaments. 7, Their origin, within the angle 
of the thyroid cartilage. 9, Their termination, at the base of the arytenoid cartilages. 
8, 10, The glottis. 

594. The larynx is connected by muscles with the sternum, 
oesophagus, base of the skull, hyoid bone, lower jaw, and 
tongue. This organ is supplied with a large number of blood- 
vessels, and it likewise receives nerves from the sympathetic 
system, and two large nerves from the tenth pair. The num- 
ber and size of the nervous filaments distributed to the 
mucous membrane of the larynx, render it more sensitive 
than any other portion of the respiratory organs. 

How is the glottis enlarged or contracted ? Explain fig. 106. 594. By 
what means and to what organs is the larynx connected ? Why is the 
larynx more sensitive than other parts of the respiratory organs ? 



272 ANATOMY, PHYSIOLOGY, AND HYGIENE. 

595. The larynx is much more developed and prominent 
in man than in woman. In the former, the anterior angle of 
the thyroid cartilage is acute, while in the latter it is rounded, 
and the central slope of the superior border of the same carti- 
lage is less deep, and the epiglottis smaller and less prominent, 
than in man. 

596. The difference in the formation of the larynx in 
infancy is less striking; but at a later period, it is more 
developed in the male than in the female. It is very remark- 
able that this increase is not progressive, like that of other 
organs, but, on the contrary, develops itself at once at the 
period of puberty. 



PHYSIOLOGY OF THE VOCAL ORGANS. 

597. In the formation of the voice, each part already 
described performs an important office. The cricoid and 
thyroid cartilages give form and stability to the larynx ; the 
arytenoid cartilages, by their movement, vary the width of the 
glottis. The epiglottis is flexible and elastic. When it is 
erect, the chink of the glottis is open, as in inspiration ; when 
depressed, as in swallowing food and drink, it covers and 
closes this aperture. It prevents the introduction of articles 
of food into the trachea, and probably modifies sound as it 
issues from the glottis. 

598. The muscles of the neck elevate and depress the 
larynx; the muscles of the larynx increase or diminish the 
width of the glottis; at the same time, the vocal cords are 

595. "What difference between the formation of the larynx of the female 
and that of the male ? 596. Does this difference exist in childhood ? Is 
its development progressive ? 597 — 600. Give the physiology of the vocal 
organs. 597- "Which cartilages give stability and form to the larynx ? 
Which vary the width of the glottis ? What is the function of the epi- 
glottis ? 598. What effect have the muscles of the neck upon the larynx ? 
The use of the muscles of the larynx ? 



PHYSIOLOGY OF THE VOCAL ORGANS. 273 

relaxed or tightened, while the muscles of the face open and 
close the mouth. 

599. The elasticity of the ribs and the contraction of the 
abdominal muscles diminish the cavity of the chest, and the 
air, in consequence, is pressed from the air-cells into the 
bronchial tubes and trachea. It then rushes by the vocal 
cords, and causes a peculiar vibration, which produces sound. 

Observatiojis. 1st. Experiments have satisfactorily shown 
that the vocal cords are the principal agents in the formation of 
the voice. The tongue, which many have supposed to be the 
most important organ in speaking, is not essential to sound. 
In several instances it has been removed, and the persons 
thus mutilated could speak with fluency. 

2d. When the vocal cords are ulcerated, or inflamed, how- 
ever slightly, as in sore throat produced by a cold, the voice 
will be changed. The loss of speech among public speakers 
is generally produced by a relaxation of the vocal ligaments. 
Hence, bronchitis is a misnomer for this affection. 

600. Sound is varied by the velocity of the expelled cur- 
rent of air, and the tension of the vocal ligaments. The size 
of the larynx, the volume and health of the lungs, the condi- 
tion of the fauces and nasal passages, the elevation and 
depression of the chin, the development and freedom of 
action of the muscles which are attached to the larynx, the 
opening of the mouth, the state of the mind, and general 
health of the system, influence the modulations of sound, 

"What effect has the combined action of these muscles ? 599. How is 
sound produced ? "What have experiments shown ? What effect has dis- 
ease of the vocal ligaments upon the voice ? 600. How is sound varied ? 
Mention other conditions that contribute to the modulation of sound. 



274 



ANATOMY, PHYSIOLOGY, AND HYGIENE. 



CHAPTER XXX. 

HYGIENE OF THE VOCAL ORGANS. 

601. The voice can be changed and modified by habit. 
Sailors, smiths, and others, who are engaged in noisy occupa- 
tions, exert their vocal organs more strongly than those of 
more quiet pursuits. This not only affects the structure of 
the vocal organs, but varies the intonation of the voice. 

602. The voice is strong in proportion to the development 
of the larynx, and the capacity of the chest. Singing and 
reading aloud improve and strengthen the vocal organs, and 
give a healthy expansion to the chest. The enunciation of 
the elementary sounds of the English language, aids in devel- 
oping the vocal organs, as well as preventing disease of the 
throat and lungs. This exercise also conduces to the acqui- 
sition of musical sounds. 

603. The attitude affects the modulation of the voice. 
When an individual stands erect, the movements of the whole 
respiratory apparatus are most free and effective. The 
larynx is brought forward by the erect position of the head 
and the elevation of the chin. The muscles of the arytenoid 
cartilages are then brought to a proper relation for action, by 
which a tension of the vocal cords is produced, that favors 
clear and harmonious enunciation. 

Experiment. Read with the head bowed forward and the 
chin depressed ; then read with the head erect and the chin 
elevated, and the difference in the movement of the vocal 



601 — 616. Give the hygiene of the vocal organs. 602. How may the voice 
be strengthened ? 603. What effect has the erect attitude upon the mod- 
ulations of the voice ? Give the experiment. 



HYGIENE OF THE VOCAL ORGANS. 275 

organs, together with the difference in the voice, will be 
manifest. 

Msr. 107. Figf. 108. 





Fig. 107. An improper position ; but one not unfrequently seen in some of our 
common schools, and in some of our public speakers. 

Fig. 103. The proper position for reading, speaking, and singing. 

604. If an individual or class read or sing when sitting, 
let the position represented by fig. 109 be adopted, and not 
the one represented by fig. 110 ; for the erect position in 
sitting conduces to the free and effective action of the res- 
piratory and vocal organs, and is as important as the erect 
attitude in standing. 

604. "What position should be adopted when a person reads or sings 
when sitting ? Why ? 



276 



ANATOMY, PHYSIOLOGY, AND HYGIENI. 



605. The muscles of the neck should not be cor, 
the muscles of the neck and larynx are compres; 
cravat, or other close dressing, not only will t 
energetic movements of these parts be impeded, i 
will be feeble and ineffective. Therefore the 
neck, particularly of public speakers and sing 
loose and thin. For a warm dress upon the 1 
vocal organs are in action, will induce too great x 
to these parts, which will be attended by sub? 

Fig. 109. 




Observations. 1st. The loss of voice, (lar-yn-gi'tis,) which 
is prevalent among public speakers, may be ascribed in part 
to the injudicious dressing of the neck, and improper position 
in standing. 



605. How should public speakers dress their necks ? "Why ? What is 
a common cause of the loss of voice ? 



HYGIENE OF THE VOCAL OR&ANS. 



277 



2d. When individuals have been addressing an audience in 
a warm room, or engaged in singing, they should avoid al". 
impressions of a cold atmosphere, unless adequately pro- 
tected by an extra garment. 

Fig. 110. 




606. The condition of the air modifies speaking and sing- 
ing. As pure air is more elastic and resonant than impure, 
and as easy, melodious speaking or singing requires atmos- 
pheric elasticity, so school-rooms and singing-halls should be 
well ventilated, if we would be entertained with soft intona- 
tions in reading, or sonorous singing. 

Observation. The imperfect ventilation of churches and 
vestries is another cause of laryngitis among clergymen. 



Give 2d. observation. 606. "Why does easy and melodious speaking 
require pure air ? What is another cause of laryngitis among clergymen ? 

24 



278 



ANATOMY, PHYSIOLOGY, AND HYGIENE. 



This affection is almost unknown among those who speak in 
veiy open rooms, where stoves are not used. 

607. The condition of the nasal passages and throat 
modifies the voice. The enunciation of words is rendered 
more or less distinct, in proportion as the jaws are separated 
in speaking, and the fauces and nasal passages are free from 
obstruction. For these reasons, the scholar should be taught 
to open the mouth adequately when reading, speaking, or 
singing, that the sounds formed in the larynx and modified in 
the fauces may have an unobstructed egress. 

Observations. 1st. If the fauces are obstructed by enlarged 
tonsils, (a condition by no means uncommon in children,) 
they should be removed by a surgical operation, which is not 
only effective, but safe, and attended with little suffering. 
The tonsils are situated on each side of the base of the 
tongue, and, when enlarged, they obstruct the passage through 
which the air passes to and from the lungs, and the respiration 
is not only laborious, but distressing. 

2d. When the nasal passages are obstructed, there is a 
peculiar sound of the voice, which is called " talking through 
the nose." This phenomenon arises, not from the expired 
air passing through the nose, but from its not being able to 
pass through the nasal passages. 

608. The state of the mind and health exerts an influence 
upon the vocal organs. " The organs of the voice, in common 
with all other parts of the bodily frame, require the vigor and 
pliancy of muscle, and the elasticity and animation of mind, 
which result from good health, in order to perform their 
appropriate functions with energy and effect. But these indis- 
pensable conditions to the exercise of vocal organs, are, in 
the case of most learners, very imperfectly supplied." 



607. Does the condition of the throat and nasal passages modify the voice ? 
Name the influences that produce clear enunciation of words. What is ther 
effect when the nasal passages are obstructed ? 608. How are the vocal 
organs influenced ? What do they require ? 



HYGIENE OF THE VOCAL ORGANS. 279 

609. " A sedentary mode of life, the want of invigorating 
exercise, close and long-continued application of mind, and, 
perhaps, an impaired state of health, or a feeble constitution, 
prevent, in many instances, the free and forcible use of those 
muscles on which voice is dependent. Hence arises the 
necessity of students of elocution practising physical exercises 
adapted to promote general muscular vigor, as a means of 
attaining energy in speaking; the power of any class of 
muscles being dependent on the vigor of the whole sys- 
tem." 

610. " Gymnastic and calisthenic exercises are invaluable 
aids to the culture and development of the voice, and should 
be sedulously practised when opportunity renders them acces- 
sible. But even a slight degree of physical exercise, in any 
form adapted to the expansion of the chest and to the freedom 
and force of the circulation, will serve to impart energy and 
glow to the muscular apparatus of voice, and clearness to its 
sound." 

611. "There is, therefore, a great advantage in always 
practising some preliminary muscular actions, as an imme- 
diate preparation for vocal exercises. The art of cultivating 
the voice, however, has, in addition to the various forms of 
corporeal exercise, practised for the general purpose of pro- 
moting health, its own specific prescription for securing the 
vigor of the vocal organs, and modes of exercise adapted to 
the training of each class of organs separately." 

612. The results of such practice are of indefinite extent. 
They are limited only by the energy and perseverance of the 
student, excepting perhaps in some instances of imperfect 
organization. A few weeks of diligent cultivation are usually 
sufficient to produce such an effect on the vocal organs, that 

609. Why are students of elocution in general necessitated to practise 
physical exercise ? 610. "What are invaluable aids in the culture of the 
voice ? 611. "What is said of the art of cultivating the voice ? 612. Are 
the results of such practices limited ? What exception ? 



280 ANATOMY, PHYSIOLOGY, AND HYGIENE. 

persons who commence practice with a feeble and ineffective 
utterance, attain, in that short period, the full command of 
clear, forcible, and varied tone. 

613. Repetition is essential to distinct articulation of 
words. In teaching a child to articulate a letter or word, in 
the first instance, make an effort to induce a proper state of 
the vocal organs by which the particular sound is produced. 
Repeat the letter or word again and again, until all the parts 
of the vocal apparatus harmonize in their movements to pro- 
duce the given sound. This repetition is as necessary in 
learning to read as in singing. 

Observations. 1st. There is nothing gained by trying to 
teach a child to pronounce the letters of the alphabet, before 
the vocal organs are so developed that distinct utterance can 
be given to the proper sounds. 

2d. The drawling method of talking to young children, as 
well as using words that are not found in any written language, 
(called child's talk,) is decidedly wrong. A child will pro- 
nounce and understand the application of a correct word as 
quickly as an incorrect one. 

614. No part of the vocal organs is wanting, with those 
individuals that stammer, or who have an impediment in their 
speech. Some parts may be more developed than others, but 
they generally are but imperfectly under the control of the 
will, and assume an irregular and rapid movement, while other 
parts, the motions of which are essential, remain compara- 
tively inactive. This can be seen by comparing the move- 
ments of the lips, tongue, and larynx, while attempting to 
speak, in a person who stammers, with the movements of the 
corresponding parts, while speaking, in an individual who has 
no such impediment. 

613. Is repetition essential to distinct articulation ? What method is 
suggested in teaching a child to articulate letters or words ? Give obser- 
vation 1st. Observation 2d. 614. Are the vocal organs wanting in 
stammerers ? Why the defect in their articulation of words ? 



HYGIENE OF THE VOCAL ORGANS. 281 

615. Surgical operations and medical treatment are not 
highly advantageous in a majority of these cases. In the 
young and middle aged, this defect can he remedied by patient 
and judicious training. At first, only those letters and words 
should be spoken that can be articulated with distinctness. 
Let there be repetition, until the words can be spoken at any 
time with readiness. Then take for a lesson other words, 
more difficult to articulate ; and pursue a similar process of 
training and repetition, until every part of the vocal organs 
can be called into a ready and harmonious action in giving 
utterance to any word in common use. 

616. The method of removing foreign bodies from the 
throat. It is not necessary to ascertain which passage the 
foreign body is in, for the immediate treatment ought in either 
case to be the same. Some person should place one hand on 
the front of the chest of the sufferer, and, with the other, give 
two or three smart blows upon the back, allowing a few 
seconds to intervene between them. This treatment will gen- 
erally be successful, and cause the substance to be violently 
thrown from the throat. 

Observation. If the foreign body passes into the larynx, 
violent spasmodic coughing immediately succeeds, which con- 
tinues until it is removed or life is extinct. Such cases de- 
mand the prompt opening of the trachea below the larynx by 
a skilful surgeon. 

615. How can stammering be remedied ? 616. What is the method of 
removing foreign bodies from the throat ? 

24* 



282 ANATOMY, PHYSIOLOGY, AND HYGIENE. 



CHAPTER XXXI. 

THE SKIN. 

617. The skin is a membrane which envelops the bones 
and other parts of the system. In youth, and in females par- 
ticularly, it is smooth, soft, and elastic. In middle age, and 
in males, it is firm and rough to the touch. In old age, in 
persons who are emaciated, and about the flexions of the joints, 
it is thrown into folds. The interior of the body, like the 
exterior, is covered by a skin, which, from the constantly 
moistened state of its surface, is called the mucous mem- 
brane. At the various orifices of the body, the exterior skin 
is continuous with the internal. 



ANATOMY OF THE SKIN. 

618. The skin, to the naked eye, appears composed of one 
membrane. But examination has shown that it consists of 
two layers of membrane, namely, the Cu'ti-cle, (scarf-skin,) 
and the Cu'tis Ve'ra, (true skin.) These layers are widely 
different from each other in structure, and perform very dif- 
ferent offices in the animal economy. 

619. The cuticle (sometimes called the ep-i-derm'is) is 
the external layer of the skin. This membrane is thin and 

617. What is the skin ? Mention its different appearances in its differ- 
ent conditions in the human frame. Is the interior of the body, as well 
as the exterior, covered by a skin ? What is the interior membrane called ? 
Why has it received this name ? 618 — 636. Give the anatomy of the skin. 
618. What is said of the skin ? What is said relative to these layers 
of membrane? 619. Describe the cuticle. What name is sometimes 
applied to the cuticle ? 



ANATOMY OF THE SKIN. 283 

semi-transparent, and resembles a thin shaving of soft, clear 
horn, and bears the same relation to other parts of the skin 
that the rough bark of a tree does to the liber, or living bark. 
The cuticle has no perceptible nerves or blood-vessels ; con- 
sequently, if it is cut or abraded, no pain will be felt, and no 
fluid will ooze from it. 

Experiment. Pass a pin through the portion of the cuti- 
cle that skirts the nails, or remove a thin shaving from the 
palm of the hand, and no painful sensation will be expe- 
rienced unless the pin or knife penetrates deeper than the 
cuticle. 

620. This membrane varies in thickness on different parts 
of the body, — from the thin, delicate skin upon the internal 
flexions of the joints, to the thickened covering of the soles 
of the feet. The greater thickness of the cuticle of the 
palms of the hands and soles of the feet, is manifestly the 
intentional work of the Creator ; for it is perceptible in 
infants, even at birth, before exercise can have had any influ- 
ence. 

621. The cutis vera (sometimes called the co'ri-on) is 
composed of minute fibres, which are collected into small 
bundles or strands. These are interwoven with each other 
so as to constitute a firm, strong, and flexible web. In the 
superficial part of the true skin, the web is so close as to have 
the appearance of felt-cloth ; but more deeply, the pores 
become progressively larger, and, upon the lower surface, 
have a diameter of about a line, or one twelfth of an inch. 
This gives the under surface the appearance of a coarse web. 
The strands of the under surface of the true skin are con- 
nected with the fibrous web, in which the sub-cutaneous fat 
of the body is deposited ; while the upper surface gives 

Give the experiment. 620. "What is said of the thickness of the cuticle 
in different parts of the body ? 621. Describe the cutis vera. By what 
name is it sometimes called ? What is the appearance of the upper sur- 
face of the cutis vera ? Of the under surface ? 



284 



ANATOMY, PHYSIOLOGY, AND HYGIENE. 



support to the sensitive, or papillary layer, which is bedded 
upon it. 

Observation. When the skins of animals are immersed in 
a strong solution of oak or hemlock bark, a chemical union 
takes place between the gelatin, of which the true skin is 
mostly composed, and the tannin of the bark. By this process 
leather is formed, and its peculiar markings are owing to the 
papillary layer 

Fig. 111. 




Fig. 111. An ideal representation of the papilla;. 1, 1, The cutis vera. 2, 2, The 
papillary layer. 3, 3, The arteries of the papilla?. 4, 4, The veins of the papilla;. 
5, 5, The nerves of the papillae. 



622. The sensitive layer of the skin is thin, soft, uneven, 
pinkish in hue, and composed of blood-vessels, which confer 
its various tints of red ; and of nerves, which give it the facul- 
ty of sensation. The unevenness of this layer is produced 
by small, elongated, conical prominences, called Pa-pil'lce. 
■ 623. Each papilla is composed of a minute artery, vein, 
and nerve. Some of the prominences are arranged in concen- 

How is leather formed ? 622. "What is the appearance of the sensitive 
layer? "What causes the unevenness of this layer? Explain fig. 111. 
623. Describe the papilla;. 



ANATOMY OF THE SKIN. 285 

trie ovals, as may be seen on the ends of the fingers ; others 
are more or less parallel, and pursue a serpentine course ; 
some suddenly diverge, and again reunite, as may be seen in 
the palm of the hand. Papillae are found in every part of the 
skin. Consequently, their number is very great. 

624. The cutis vera contains not only Arteries, Veins, and 
Nerves, but Lymphatics, Oil- Glands and Tubes, and Perspi- 
ratory Glands and Tubes. 

Fig. 112. 




Fig. 112. The arteries and veins of a section of the skin. A, A, Arterial branches. 
B, B, Capillary, or hair-like vessels, in which the large branches terminate. C, The 
venous trunk, collecting the blood from the capillaries. 

625. The arteries and veins of the skin are very numer- 
ous. The larger branches of the arteries pass through the 
open meshes of the true skin, and are subdivided into a 
myriad of minute capillary vessels, which form a beautiful 
net -work on the upper surface of the true skin. This vascu- 
lar net sends a branch to each of the papilla?, which opens 
into and terminates in a minute vein. The capillary veins are 



624. "What vessels are found in the cutis vera? Explain fig. 112. 
625. "What is said of the cutaneous arteries ? Of the cutaneous veins ? 



286 ANATOMY, PHYSIOLOGY, AND HYGIENE. 

as numerous as the arteries which they accompany. They 
unite and form larger trunks, as small springs from the hill- 
side coalesce to form rivulets. 

626. The nerves that are spread over every part of the 
sensitive layer of the true skin, proceed from the spinal cord. 
As a proof of the great number of nervous filaments in the 
skin, no part of this tissue can be punctured with a fine 
needle without transfixing a nerve, and inducing pain. In 
some parts of the system, however, the nerves are more 
abundant than in others ; where the sense of feeling is most 
acute, we find the greatest number of nerves, and those of the 
largest size. Those parts that are most exposed to injury are 
most sensitive. 

Examples. 1st. The conjunctiva, or skin of the eye, is 
pained by the presence of a particle of dust, because it 
would render vision imperfect. 

2d. The lungs, also, would be injured by the smallest par- 
ticle of matter ; they are therefore protected by the exquisite 
sensitiveness of the lining membrane of the trachea, so that 
a particle of food or dust is ejected by a convulsive cough 
before it reaches the lungs. 

627. The nerves are more numerous in the upper than 
lower extremities ; in greater numbers upon the palm than 
the back of the hand. They are, likewise, more abundant 
and larger at the extremities of the fingers, and in the lips, 
than in any other part of the skin. 

Observation. The proboscis of the elephant, the extremities 
of the tails of certain species of monkeys, and the tentacula 
of some kinds of fish, receive a more abundant supply of sen- 
sitive nerves than other parts of their systems. 

626. "Where do the nerves of the skin proceed from ? Are they numer- 
ous in this membrane ? How is it proved ? What is said of those parts 
most exposed to injury ? Give example 1st. Example 2d. 627. Mention 
the difference in the distribution of the nerves in various parts of the 
body. Is this difference found in the lower order of animals ? 



ANATOMY OF THE SKIN. 



287 



628. In the small papillss, the nerve forms a single loop, 
while in papillse of larger size, and endowed with a power 
of more exalted sensation, the nerve is bent several times 
upon itself previous to completing the loop. These little 
loops spring from a net-work of nerves, imbedded in the 
upper porous layer of the true skin, at the base of the papil- 
lse. This net-work of nerves receives its influence through 
nerves which take their winding course through the fat dis- 
tended openings of the deeper layers of the true skin. 

Fig. 113. 




Fig. 113. 1, 1, The cuticle. 2, 2, The colored layer of the cuticle. 3, 3, The 
papillary layer, exhibiting the nerves as they form loops. 4, 4, The net-work of 
nerves. 5, 5, The true skin. 6, 6, 6, Three nerves that divide to form the net- 
work (4, 4.) 7, 7, 7, The furrows between the papilla?. 8, 8, 8, Three papilla? 
magnified fifty diameters. 

629. The lymphatics are found in great numbers in the 
true skin, and they are so minute that they cannot be seen with 
the naked eye ; but when these hair-like vessels are injected 
with quicksilver, (a work of great difficulty,) the surface injected 



628. How are the nerves of the small papilla? arranged ? How in the 
large papillae ? What does fig. 113 represent ? 629. What is said of the 
cutaneous lymphatics ? How is their existence proved ? 



288 ANATOMY, PHYSIOLOGY, AND HYGIENE. 

resembles a sheet of silver. In this way their existence can 
be imperfectly demonstrated. They are a part of the vascu- 
lar net- work situated upon the upper surface of the true skin. 
Each papilla is supplied with a lymphatic filament, the mouth 
of which opens beneath, and lies in contact with the under 
surface of the cuticle. This net-work of vessels communi- 
cates through the open meshes of the true skin with larger 
lymphatic trunks, that open into the venous system. 

Fig. 114. 




Fig. 114. A plexus of lymphatic vessels in the skin, considerably magnified from 
an injected preparation. 

630. The oil-glands are small bodies imbedded in the 
true skin. They connect with the surface of the skin by small 
tubes, which traverse the cuticle. In some parts, these glands 
are wanting ; in others, where their office is most needful, 
they are abundant, as on the face and nose, the head, the 
ears, &c. In some parts, these tubes are spiral ; in others, 
straight. These glands offer every shade of complexity, from 
the simple, straight tube, to a tube divided into numberless 



Of what are they a part ? 630. Describe the oil-glands. "With what do 
they connect ? Do they exist in every part of the body ? Of what form 
are their tubes ? 



ANATOMY OF THE SKIN. 



289 



ramifications, and constituting a little rounded tree-like mass, 
about the size of a millet seed. 

631. In a few situations, these small glands are worthy of 
particular notice, as in the eyelids, where they possess great 
elegance of distribution and form, and open by minute pores 
along the lids ; in the ear-passages, where they produce that 
amber-colored substance, known as the ce-ru'men, (wax of the 
ears,) and in the scalp, where they resemble small clusters of 
grapes, and open in pairs into the sheath of the hair, supply- 
ing it with a pomatum of Nature's own preparing. The oil- 
tubes are sometimes called the se-ba'ceous fol'li-cles. 




Fig. 115. 1, An oil-tube and gland from the scalp. A, The gland. B, The tube 
slightly twisted. 

2. An oil-tube and gland from the skin of the nose. The gland (A) is double, and 
communicates with the main tube (B) by means of two smaller tubes. 

3. Another oil-tube and gland from the nose. A, The gland. B, The tube filled 
with the peculiar animalculae of the oily substances. Their heads are directed 
inward. 

4. A small hair from the scalp, with its oil-glands. The glands (A) form a cluster 
around the shaft of the hair-tube, (C.) These ducts open into the sheath of the 
hair, (B.) All the figures, from 1 to 4, are magnified thirty-eight diameters. 



631. "What is said of these tubes in the eyelids ? 
scalp ? What are these glands sometimes called ? 

25 



In the ear ? In the 



290 ANATOMY, PHYSIOLOGY, AND HYGIENE. 

Observation. Among the inhabitants of cities, and espe- 
cially in persons who have a torpid state of the skin, the con- 
tents of the oil-tubes become too dense and dry to escape in 
the usual manner. Thus it collects, distends the tube, and 
remains until removed by art. When this impacted matter 
reaches the surface, dust and smoke mix with it, then it is 
recognized by small, round, dark spots. These are seen on 
the forehead, nose, and other parts of the face. When this 
matter is pressed out, the tube gives it a cylindrical form, 
which, together with its size and black extremity, is popularly 
called a " worm," or " maggot." 

632. The perspiratory apparatus consists of minute 
cylindrical tubes, which pass inward through the cuticle, and 
terminate in the deeper meshes of the cutis vera. In their 
course, each little tube forms a beautiful spiral coil ; and, on 
arriving at its destination, coils upon itself in such a way 
as to constitute an oval-shaped, or globular ball, called the 
perspiratory gland. 

633. The opening of the perspiratory tube on the surface 
of the cuticle, namely, " the pores," is also deserving of atten- 
tion. In consequence of its extremity being a section of a 
spirally-twisted tube, the aperture is oblique in direction, and 
possesses all the advantages of a valvular opening, preventing 
the ingress of foreign injurious substances to the interior of the 
tube and gland. 

634. " To arrive at something like an estimate of the value 
of the perspiratory system, in relation to the rest of the organ- 
ism, I counted the perspiratory pores on the palm of the hand, 
and found 3528 in a square inch. Now each of these pores 
being the aperture of a little tube about a quarter of an inch 

What is said of the retention of the unctuous matter in the oil-tubes ? 
632. Of what does the perspiratory apparatus consist ? 633. What is 
peculiar in the opening of the perspiratory tubes on the surface of the cuti- 
cle ? 634. How many perspiratory pores did Dr. Wilson count upon a 
square inch of skin on the palm of the hand ? 



ANATOMY OF THE SKfN. 



291 




Fig. 116. A perspiratory gland from the palm of the hand, magnified forty diame- 
ters. 1, 1, A twisted tube composing the gland. 2, 2, The two excretory ducts 
from the gland. These unite to form one spiral tube, that perforates the cuticle, (3,) 
and opens obliquely on its surface at 4. The gland is imbedded in cells filled with 
fat, which are seen at 5, 5. 



"What does fig. 116 represent 



2S2 ANATOMY, PHYSIOLOGY, AND HYGIENE. 

long, it follows, that in a square inch of skin on the palm 
of the hand there exists a length of tube equal to 882 inches, 
or 73^- feet. Surely such an amount of drainage as seventy- 
three feet in every square inch of skin — assuming this to be 
the average for the whole body — is something wonderful ; 
and the thought naturally intrudes itself, What if this drainage 
be obstructed ? 

635. " Could we need a stronger argument for enforcing 
the necessity of attention to the skin ? On the pulps of the 
fingers, where the ridges of the sensitive layer of the true 
skin are somewhat finer than in the palm of the hand, the 
number of pores on a square inch a little exceeded that of the 
palm ; and on the heels, where the ridges are coarser, the 
number of pores on the square inch was 2268, and the 
length of the tube 567 inches, 47^ feet. 

636. " To obtain an estimate of the length of tube of the 
perspiratory system of the whole surface of the body, I think 
that 2800 might be taken as a fair average of the number of 
pores in the square inch ; and consequently, 700, the number 
of inches in length. Now, the number of square inches of 
surface in a man of ordinary height and bulk is 2500 ; the 
number of pores, therefore, 7,000,000 ; and the number of 
inches of perspiratory tube is 1,750,000 ; that is, 145,833 feet, 
or 48,611 yards, or nearly twenty-eight miles /" — Wilson. 

Give other computations in this paragraph. 635. What is said of the 
number of these pores on the pulp of the fingers ? On the heels ? 
636. What is an average number of pores and length of tube of the whole 
surface of the body ? Give the summary of the number of pores, and num- 
ber of inches of perspiratory tube. 



PHYSIOLOGY OF THE SKIN. 293 



CHAPTER XXXII. 

PHYSIOLOGY OF THE SKIN. 

637. The skin invests the whole of the external surface of 
the body, following all its prominences and curves, and gives 
protection to all the organs it encloses, while each of its sev- 
eral parts has a distinct use. 

638. The cuticle is insensible, and serves as a sheath of 
protection to the highly sensitive skin (cutis vera) situated 
beneath it. The latter feels ; but the former blunts the im- 
pression which occasions feeling. In some situations, the 
cuticle is so dense and thick, as wholly to exclude ordinary 
impressions. Of this we see an example in the ends of the 
fingers, where the hard and dense nail is the cuticle ntodified 
for the purpose referred to. Were the nervous tissue of the 
true skin not thus protected, every sensation would be so acute 
as to be unpleasant, and contact with external bodies would 
cause pain. 

639. The cuticle, also, prevents disease, by impeding the 
evaporation of the fluids of the true skin, and the absorption of 
the poisonous vapors, which necessarily attend various employ- 
ments. It, however, affords protection to the system only 
when unbroken, and then, to the greatest degree, when 
covered with a proper amount of oily secretion from the oil- 
glands. 

640. The cuticle is, originally, a transparent fluid, exuded 

637 — 656. Give the physiology of the skin. 637. What is said of the 
skin? 638. Give a function of the cuticle. Does it vary in thickness on 
different parts of the body ? Give examples. 639. Mention another use 
of the cuticle. 640. "What is the cuticle originally ? 

25* 



294 ANATOMY, PHYSIOLOGY, AND HYGIENE. 

by the blood-vessels, and distributed as a thin layer on the sur- 
face of the true skin. While successive layers are formed on 
the exterior of the true skin, the external cuticular layers are 
converted into dry, flattened scales, by the evaporation of their 
fluid contents. The thickness of the cuticle is formed mainly 
from these scales. 

641. The cuticle is, therefore, undergoing a constant pro- 
cess of formation and growth at its under part, to compensate 
for the wear that is taking place continually on its surface. A 
proper thickness of the cuticle is in this manner preserved ; 
the faculty of sensation ^nd that of touch are properly regu- 
lated ; the places of the little scales, which are continually 
falling off under the united influence of friction and ablu- 
tion, are supplied ; and an action necessary, not merely to 
the health of the skin, but to that of the entire body, is 
established. 

642. Whenever the cuticle is exposed to moderate and 
repeated friction, it becomes thicker and tougher, as may be 
seen in the cuticle of the lady's finger that plies the needle, 
and in the hard or callous appearance of the hands of farmers, 
masons, and other mechanics. This enables them to handle 
the utensils and materials used in their vocations without pain 
or inconvenience. 

Observations. 1st. When the joints of the feet are sub- 
jected to moderate and continued pressure or friction, fre- 
quently one or more of the papilla? enlarge. This is 
accompanied with a thickening of the layers of the cuticle, 
which is termed a " callosity," or " corn." These thickened 
layers of the cuticle are broad at the top and narrow at the 
bottom, and the enlarged mass is conical, with the point 

How is the thickness of the cuticle mainly formed ? 641. Describe the 
changes of this membrane. Show the necessity of this constant growth. 
642. How does moderate and repeated friction affect the cuticle ? Give 
examples. "What is the benefit derived from having the cuticle thus 
changed? What is the result if the joints of the feet are subjected to 
moderate and continued pressure ? What is the form of a " corn " ? 



PHYSIOLOGY OF THE SKIN. 295 

innermost. When pressed upon by a tight shoe, these sensitive 
papillae cause pain. 

2d. To remove these painful -excrescences, take a thick 
piece of soft leather, somewhat larger than the corn ; in the 
centre punch a hole of the size of the summit of the corn, 
spread the leather with adhesive plaster, and apply it around 
the corn. The hole in the leather may be filled with a paste 
made of soda and soap, on going to bed. In the morning, 
remove it, and wash with warm water. Repeat this for 
several successive nights, and the corn will be removed. The 
only precaution is, not to repeat the application so as to 
cause pain. 

643. Let a person unaccustomed to manual labor, trundle 
the hand-cart, or row a boat, for several successive hours, and 
the cuticle upon the palms of the hands, instead of becom- 
ing thicker by use, is frequently separated from the subjacent 
tissues, by an effusion of serum, (water,) thrown out by the 
vessels of the true skin. Had the friction been moderate, 
and applied at regular intervals, instead of blisters being 
formed upon the inside of the hands, material would have 
been thrown out to form new layers upon the lower surface 
of the cuticle. 

644. The cuticle is interesting to us in another point of 
view, as being the seat of the color of the skin. The differ- 
ence of color between the blonde and the brunette, the Euro- 
pean and the African, lies in the cuticle ; — in the deeper, and 
softer, and newly-formed layers of that structure. In the 
whitest skin, the cells of the cuticle always contain more or 
less of a peculiar pigment, incorporated with the elementary 
granules which enter into their composition. In the white 

How can they be removed ? What precaution is given ? 643. Explain 
why those persons unaccustomed to labor, blister their hands in rowing a 
boat or performing ordinary manual employment for several successive 
hours. 644. In what other point of view is the cuticle interesting ? In 
what part of it do we find the coloring matter ? 



296 ANATOMY, PHYSIOLOGY, AND HYGIENE. 

races, the pigmentary tint is extremely slight, and less in 
winter than in the summer season. In the darker races, on 
the contrary, it is deep and strongly marked. 

645. The various tints of color exhibited by mankind, are, 
therefore, referable to the amount of coloring principle con- 
tained within the elementary granules of the cuticle, and 
their consequent depth of hue. In the negro, the granules 
are more or less black ; in the European of the south, they 
are amber-colored ; and in the inhabitants, of the north, they 
are pale and almost colorless. 

646. Color of the skin has relation to energy in its action ; 
thus, in the equatorial region, where light and heat are most 
powerful, the skin is stimulated by these agents to vigorous 
action, and color is very deep ; while in the temperate regions, 
where light and heat are not so intense, the lungs, liver, and 
kidneys relieve the skin of part of its duties. The colored 
layer of the cuticle has been called the re'te mu-co'sum, 
(mucous coat of the skin,) and described as a distinct layer 
by many physiologists. 

Observation. " The various coloring of the inner layer of 
the cuticle gives to some animals their varied hues ; the ser- 
pent, the frog, the lizard, and some fishes have a splendor of 
hue almost equal to polished metal. The gold-fish and the 
dolphin owe their difference of color and the brilliancy of 
their hues to the color of this layer of the skin." 

647. The nerves of the skin are the organs of the sense 
of touch and feeling. Through them we receive many im- 
pressions that enhance our pleasures, as the grateful sensa- 
tions imparted by the cooling breeze in a warm day. In 



In what season of the year is the coloring matter less in the white race ? 
645. To what is the color of the skin referable ? 646. Why have the races 
of the torrid zone darker complexions than those of the temperate or frigid 
zones ? "What is this colored layer called by many physiologists ? To 
what is the different hues in animals owing ? 647. Of what use are the 
nerves of the skin ? 



PHYSIOLOGY OF THE SKIN. 297 

consequence of their sensitiveness, we are individually pro- 
tected, by being admonished of the proximity of destructive 
agents. 

Illustration. A man who had been afflicted some years 
with a severe disease of a portion of the brain and spinal 
cord, was deprived of feeling in the lower extremities. He 
was directed by his attending physician to use a warm foot- 
bath. Intending to follow the directions given him, he 
immersed his feet in boiling water, which he supposed of a 
proper temperature. While his feet were immersed in the 
water, he experienced no sensation of an unpleasant nature. 
On withdrawing them, he was astonished to find the cuticle 
separated from the other tissues, by the effusion of serum, 
and thus producing a blister over the whole surface. 

648. Portions of the skin would suffer every day, were it 
not for the sentinel-like care exercised by the nerves, by 
which all impressions are transmitted to the brain. As the 
skin is continually exposed to the influence of destructive 
agents, it is important that {he nerves, provided for its pro- 
tection, should be kept in a healthy state. 

649. A large proportion of the waste of the body passes 
through the outlets of the skin ; some portions in the form 
of oil, others in the form of water and carbonic acid. 

650. The oil-glands secrete an oil, partly free and diffused, 
and partly mixed with albumen. When the cells are fully 
formed, that is, fully distended, they yield their contents, 
and the fluid matter they contain is set free, and passes along 
the tubes to the surface ; this fluid matter constitutes the oily 
element of the economy of the skin. 

651. The uses of the unctuous product of the oil-glands 
are twofold : 1st. The protection; 2d. The removal of waste 

Give the illustration. 648. Why is it necessary that the cutaneous nerves 
be kept in a healthy state ? 649. Through what membrane does a large 
proportion of the waste material of the system pass ? 650. What is the 
function of the oil-glands ? 651. What are the uses of the oily product 
of these glands ? 



298 



ANATOMY, PHYSIOLOGY, AND HYGIENE. 



matter from the system. In the exercise of these offices the 
oily substance is diffused Over those parts of the skin which 
are naturally exposed to vicissitudes of temperature and 
moisture, — as the nose, face, and head; — to the injurious 
attrition of contiguous surfaces, — as the flexures of joints ; — 
or the contact of acrid fluids, — as in the excoriations to which 
infants are liable. 

652. The oil of the unctuous substance is the principal 
agent in effecting these purposes : 1st. It prevents the evap- 
oration or congelation of the water of the cuticle, which 
would cause it to become parched and peel off, thus leaving 
the sensitive skin exposed. 2d. It affords a soft medium to 
the contact of moving substances. 3d. It repels moisture and 
fluids. 4th. The action of these glands removes the waste 
atoms and purifies the blood. 

653. In considering the purpose of the oily matter of the 
skin, there are two situations in which it deserves especial 
remark. 1st. Along the edges of the eyelids, where it is 
poured out in considerable quantity. Here, it is the means 
of confining the tears and moisture of the eyes within the 
lids, defending the skin from the irritation of that fluid, and 
preventing the adhesion of the lids, which is liable to occur 
upon slight inflammation. 2d. In the ears, where the unctuous 
wax not only preserves the membrane of the drum and the 
passage of the ear moist, but also, by its bitterness, prevents 
the intrusion of small insects. 

654. The use of the perspiratory glands is to separate from 
the blood that portion of the waste matter which is carried 
off through the skin in the form of vapor. Sanctorius, a 
celebrated medical writer, daily, for thirty years, weighed 

652. What prevents the evaporation of the water of the cuticle ? Give 
its 2d use. Its 3d. Its 4th. 653. What is said in reference to the dis- 
tribution of the oily matter along the edges of the eyelids ? In the ears ? 
654. Of what use are the perspiratory glands ? How long did Sanctorius 
daily weigh his food, to ascertain the amount of secretion that passed 
through the skin ? 



PHYSIOLOGY OF THE SKTN. 299 

himself, his food, and excretions. He estimated that five of 
every eight pounds of food and drink passed from the system 
through the many outlets upon the skin. Many place the 
estimate much lower. All physiologists agree that from 
twenty to forty ounces of matter pass off from the skin of an 
adult every twenty- four hours. 

655. The average amount of perspiration is about thirty 
ounces ; and it passes off in such minute portions, and mixes 
so rapidly with the surrounding air, that it is not perceived. 
For this reason, it is called insensible perspiration. When 
this excretion is increased, it forms into drops, and is called 
sensible perspiration. The following experiments prove the 
existence of this excretion from the skin. 

Experiments. 1st. Take a cold bell-glass, or any glass 
vessel large enough to admit the hand, and introduce it per- 
fectly dry ; at the same time close the mouth by winding a 
napkin about the wrist ; in a short time, the insensible per- 
spiration from the hand, will be seen deposited on the inside 
of the glass. At first, the deposit is in the form of mist ; but, 
if the experiment be continued a sufficient time, it will collect 
in drops. 

2d. Hold the apparently dry hand near a looking-glass, and 
the invisible vapor will soon be condensed, and cover the glass 
with a slight dew. 

656. It is important that this excretion be maintained with 
steadiness and regularity. When the action of the perspira- 
tory glands is suppressed, all the vessels of the different 
organs will suffer materially, and become diseased, by the 
redundant waste matter that should be carried from the system. 
If a person is vigorous, the action of the organs, whose 



"What were his conclusions ? 655. What is the average amount of per- 
spiration every twenty-four hours ? What is insensible perspiration ? 
What is sensible perspiration ? How can the existence of the excretion of 
the skin be shown ? Give the 2d experiment. 656. Why is it important 
that these excretions be maintained regularly ? 



300 



ANATOMY, PHYSIOLOGY, AND HYGIENE. 



functions are similar to those of the skin, as channels for 
the exit of waste matter, will be increased, and thus relieve 
the diseased state of the body. But the over-taxing of these 
organs, to relieve the system, often produces a diseased action 
in themselves. 

Fig. 117. 




Fig. 117. 1, 1, The lines, or ridges of the cuticle, cut perpendicularly. 2, 2, 2, 2, 2, 
The furrows, or wrinkles of the same. 3, The cuticle. 4, 4, 4, The colored layer of the 
cuticle. 5, 5, The cutis vera. 6, 6, 6, 6, 6, The papillae. 7, 7, Small furrows between 
the papillae. 8, 8, 8, 8, The deeper furrows between each couple of the papilla?. 9, 9, 
Cells filled with fat. 10,10,10, The adipose layer, with numerous fat vesicles. 11, 
11, 11, Cellular fibres of the adipose tissue. 12, Two hairs. 13, A perspiratory gland, 
with its spiral duct. 14, Another perspiratory gland, with a duct less spiral. 15, 15, 
Oil-glands with ducts opening into the sheath of the hair, (12.) 



Note. — Let the pupil review the anatomy and physiology of the skin from 
fig. 117, or from anatomical outline plate No. 9. 



HYGIENE OF THE SKIN. 301 



CHAPTER XXXIII. 

HYGIENE OF THE SKIN. 

657. The sensibility of the skin, and the activity of the 
oil and perspiratory glands, are modified by the condition 
of the cuticle, the temperature of the skin and body, the 
purity and warmth of the air, and the character of the light 
to which the body is exposed. Thus, to maintain a healthy 
action of every part of this membrane, attention should be 
given to Clothing, Bathing, Light, and Air. 

658. Clothing, in itself, does not bestow heat, but is 
chiefly useful in preventing the escape of heat from the body, 
and in defending it from the temperature of the atmosphere. 
In selecting and applying clothing to our persons, the follow- 
ing suggestions should be observed. 

659. The material for clothing should be a bad conductor 
of heat ; that is, it should have little tendency to conduct or 
remove heat from the body. This depends mainly on the 
property possessed by the material in retaining atmospheric 
air in its meshes. 

660. The material for clothing should not possess the 
property of absorbing and retaining moisture. Dampness, 
or moisture, renders apparel a good conductor of heat; beside, 
if the perspired fluid, and the saline material it holds in solu- 
tion, are readily absorbed by the clothing, they become 

657 — 716. Give the hygiene of the shin. 657. What influences modify 
the action of the oil and perspiratory glands ? To what must atten- 
tion be given to maintain a healthy action of the skin ? 658. What is 
said in regard to the clothing ? 659. Mention a property that the material 
for clothing should possess. 660. What property in the selection of cloth- 
ing should we avoid ? Why ? 

26 



302 ANATOMY, PHYSIOLOGY, AND HYGIENE. 

sources of irritation to the skin with which the apparel comes 
in contact. 

661. Furs contain a greater amount of air in their meshes, 
than any other article, and they absorb no moisture ; conse- 
quently, as an article of dress, they are best adapted to those 
who are exposed to great vicissitudes of heat and cold. 

662. Woollen cloth retains more air in its meshes than 
any other article except furs and eider down, and it absorbs 
but very little moisture. These properties, together with its 
comparative cheapness, render it a good article of apparel for 
all classes of persons. The only objection to its general use 
is, the disturbance of the electricity of the system, and the 
irritation to delicate skins from the roughness of its fibres. 

Observation. Flannels are not only beneficial, during the 
cold season, in preventing colds and rheumatism, but they are 
of great utility in the warm season, in shielding the system 
from the chills at evening, that induce disease of the alimen- 
tary canal. Their general use among children and delicate 
females, would be a preventive of the " season complaints " 
prevalent in the months of August and September. 

663. Cotton contains less air in its meshes than woollen, 
but much more than linen. In texture, it is smoother than 
wool, and less liable to irritate the skin. This fabric absorbs 
moisture in a small degree. In all respects, it is well adapted 
for garments worn next the skin. When woollen flannels 
irritate the skin, they may be lined with cotton. 

664. Silk is not as good a conductor of heat as cotton, nor 
does it absorb moisture to any considerable degree ; its texture 
is smooth, and does not irritate the skin ; consequently, when 
the garment of this fabric has sufficient body or thickness, it 

661. Give the properties of fur. As an article of dress, to whom are they 
best adapted ? 662. Give the properties of woollen cloth. Is this a good 
article for clothing ? "What objection ? What are the advantages of 
wearing flannels ? 663. What are the qualities of cotton as an article of 
dress ? 664. Of silk ? 



HYGIENE OF THE SKIN. 303 

is a good article for clothing. The greatest objection to its 
use, is the disturbance of the electricity of the system, and 
its high price. 

665. Linen is not only a good conductor of heat, and 
consequently a poor article of apparel, but it likewise absorbs 
the fluids carried from the system by the" agency of the oil 
and perspiratory glands. When garments are made of this 
material, the body is not surrounded by a layer of air, but by 
one of moisture. This still further increases its power to 
conduct heat from the system, rendering it a very objectiona- 
ble article of apparel, even in warm weather and in hot 
climates, where the dress is usually thin. 

666. Clothing differs in its power of radiating heat. 
This is influenced by the color ; those articles that radiate 
heat freely also absorb it readily. A black surface is a good 
radiator, while a white surface is not, because it reflects the 
calorific rays. It is obvious that those colors which render 
the transmission of external heat difficult, must impede the 
transmission of caloric from the body. Thus it is manifest, 
that light-colored apparel is best adapted for every season and 
every climate. 

Observation. Coach-drivers are practically aware, that in 
cold weather, light-colored over-coats are warmest, except 
when they are exposed to the direct rays of the sun, or when 
seated before a warm fire. On the other hand, when the 
temperature is elevated, light-colored apparel is coolest, be- 
cause the sun's rays are then reflected. 

667. The clothing should he of a porous character. The 
skin is not only an important agent in separating from the 
blood those impurities that otherwise would oppress the system 
and occasion death, but it exercises great influence upon the 
system, by receiving oxygen through its tissues, and giving 

665. What is said of linen as an article of apparel ? 666. Why is light- 
colored apparel best adapted for every season ? What is said of the ap- 
parel of coach-drivers ? 667. Why should we wear porous clothing ? 



304 ANATOMY, PHYSIOLOGY, AND HYGIENE. 

back carbonic acid in return. Consequently, the apparel 
should be made of a material that will permit free trans- 
piration from the skin, and likewise convey the excreted fluids 
from the surface. 

668. The necessity for this is illustrated in wearing India 
rubber over-shoes. If they are worn over boots ten or twelve 
hours, not only the hose, but the boots will be moist from 
retained perspiration, and the residual matter left in contact 
with the skin may be reconveyed into the system by absorp- 
tion, causing headache and other diseases. Cotton and wool- 
len fabrics are not only bad conductors of heat, but are also 
porous ; for these reasons, they are well adapted to transmit 
the excretions of the skin. 

669. The clothing should be not only porous, but fitted 
loosely. The garments should retain a layer of air between 
them and the body. Every one is practically aware that a 
loose dress is much warmer than one which fits closely ; that a 
loose glove is warmer than a tight one ; and that a loose boot 
or shoe affords greater warmth than one of smaller dimen- 
sions. The explanation is obvious ; the loose dress encloses 
a thin layer of air, which the tight dress is incapable of 
doing ; and what is required, is, that the dress should be 
closed at the upper part, to prevent the dispersion of the" 
warm air, by the ventilating current which would be estab- 
lished from below. 

Observation. As the purpose of additional garments is to 
maintain a series of strata of warm air within our clothing, we 
should, in going from a warm room into the cold air, put on 
our defensive coverings some little time previous, in order 
that the layers of air which we carry with us may be suffi- 
ciently warmed by the heat of the room, and not borrowed 
from the body on exposure to the cold. 

668. How is the necessity of porous clothing illustrated ? 669. "Why 
should we wear loose garments ? "What is the use of additional garments 
when going from a warm to a cold air ? "When should they be put on ? 



HYGIENE OF THE SKIN. 305 

670. The clothing should he suited to the temperature of the 
atmosphere and the condition of the individual. The invari- 
able rule should be, to wear enough to maintain an equal and 
healthy action of the skin. Care should be taken, however, 
that the action of the cutaneous vessels is not inordinately- 
increased, as this would debilitate, not only the skin, but the 
internal organs of the system, as the stomach and lungs. 

671. No rule as to the quantity of clothing can be given, 
as the demand will vary with different individuals. The fol- 
lowing are among the most prominent causes of this variation : 
Those persons who have large, active brains, full chests, well 
developed lungs, breathe an adequate amount of pure air, and 
take sufficient food to supply the wants of the system, require 
less clothing than those of an opposite character, because 
more heat is generated in the system. 

672. The child and the aged person require more clothing 
than the vigorous adult. Should we judge from observation, 
the inference would be, that children require less clothing 
than adults. This is an error, for the temperature in infancy 
is not only lower than in manhood, but the power of creating 
heat is feebler. The same remarks are applicable to those 
persons who have outlived the energies of adult life. 

Observation. The system of " hardening " children, by an 
inadequate supply of clothing, and keeping them uncomfort- 
ably cold throughout the whole day, is inhuman, as well as 
unprofitable. It operates upon the child somewhat like the 
long-continued chill upon a certain portion of the farmer's 
hgrd, that are kept shivering under the thatched shed, retard- 
ing the growth of their systems, which require more food to 
satisfy the keen cravings of hunger than when they are com- 

670. What should be the invariable rule in reference to the amount of 
clothing that should be worn ? What precaution should be observed ? 
671. What are some of the causes of the variation of the demand for 
clothing ? 672. Why do the child and aged person require more clothing 
than the vigorous adult ? What is said of the system of hardening 
children ? 

26* 



306 ANATOMY, PHYSIOLOGY, AND HYGIENE. 

fortably sheltered. To make the boy robust and active, he 
must have nutritious food at stated hours, and free exercise in 
the open air, and his system must be guarded from chills by a 
due amount of apparel. 

673. More clothing . is needed when a vital organ is dis- 
eased. It may be observed that in consumption, dyspepsia, 
and even in headache, the skin is pale and the extremities 
cold, because less heat is generated. Thus persons affected 
with these complaints, when exposed to cold air, need more 
clothing than those individuals whose organs are not diseased, 
and the functions of which are properly performed. 

674. More clothing is required in the evening, than 
during the day. In the evening we have less vital energy, 
and therefore less heat is generated in the system, than in the 
early part of the day; beside, the atmosphere is damp, the 
skin has become moist from free perspiration, and heat, in 
consequence, is rapidly removed from the system. For this 
reason, when returning from crowded assemblies, we should 
be provided with an extra garment. 

Observations. 1st. If there is a chill upon the system after 
having arrived home, warmth should be restored as speedily 
as possible. This can be done by friction with warm flannels, 
and by using the warm or vapor bath. By this procedure, 
the pernicious effects of the chill will be prevented before any 
disease is fixed upon the system. Is it not the duty of the 
parent and the guardian to learn these facts, and to see that 
they are not only learned, but reduced to practice ? 

2d. The farmer and industrious mechanic would be freed 
from many a rheumatic pain, if, while resting from their 
labors at evening, or taking the ordinary meal after hard toil, 
they would put on an extra garment. The coat might not 

673. Why do dyspeptic and consumptive persons require more clothing 
than those who have healthy vital organs ? 674. Why do we need more 
clothing in the evening than during the day ? How can the pernicious 
effects of a chill be prevented ? Give the 2d observation. 



HYGIENE OF THE SKIN. 307 

feel so agreeable for the first few minutes, but it would 
ultimately conduce to health and longevity. 

675. The 'person of active habits requires less clothing than 
one of sedentary employ ments. Exercise increases the circu- 
lation of the blood, which is always attended by the disen- 
gagement of a greater quantity of heat ; consequently, an 
increase of warmth is felt throughout the system. We like- 
wise need more clothing while riding, than when we are 
walking ; because the exercise of the former is less than that 
of the latter. The same is true when resting in the field or 
shop, after laborious exercise. 

Observation. We need a greater amount of clothing while 
asleep, than during the day ; as not only the action of the 
body, but that of the brain, during sleep, is suspended. 

676. Less clothing is required when the cutaneous surface 
is clean. A film of impurities obstructs the perspiratory 
ducts, and diminishes the action of their glands ; conse- 
quently, less heat is generated. For this reason, the hands 
or feet when clean are less liable to become chilled or frozen. 

677. The sensitiveness of the skin to the influence of cold, 
is much modified by habit. A person who has been habituated 
to the temperature of a warm room, or warm climate, suffers 
more when exposed to cold, than an individual who has been 
accustomed to colder air. Thus a person who labors or 
studies in a warm room, should wear more clothing when 
exposed to the air, while walking or riding, than an individual 
who labors in a cooler atmosphere. Not only is the sensi- 
bility of the skin increased by a warm atmosphere, but the 
activity of the digestive, respiratory, and nervous systems, in 
generating heat, is much diminished. This is an additional 
reason why an increased amount of clothing is demanded 

675. "Why does the person of active habits require less clothing than one 
of sedentar}' employments ? 676. Why do we need less clothing when 
the skin is clean ? 677. Show the effect of habit on the sensitiveness of 
the skin. 



308 ANATOMY, PHYSIOLOGY, AND HYGIENE. 

during exposure to cold air. In all cases where practicable, 
the heat of the system should be maintained by exercise, in 
preference to the use of fur or flannel. 

678. Those parts of the skin usually covered, uniformly 
need that protection. The power of generating heat is 
diminished, and the impressibility to cold is increased, on those 
portions of the skin usually clothed. If a person wears the 
dress high and close about the neck, he suffers from exposure 
to a cold atmosphere if a dress is worn that is not as high or 
more open. As a general rule, it is preferable that those 
parts of the system, as the larynx, be exposed that are not 
uniformly protected by clothing. 

679. The clothing should he kept clean. No article of 
apparel is entirely free from absorption : even wool and cotton 
possess it in a small degree. They take up a portion of the 
transpired fluids which contain saline and animal matter, and 
thus the fibres of the garments become covered with the 
cutaneous excretions. We are practically aware of the reten- 
tion of these secretions from the soiled appearance of those 
garments worn next the skin, which are so covered as to pre- 
clude the particles of dust from lodging upon them. 

680. The porosity of the clothing is lessened when soiled, 
and its power of conducting heat from the system in conse- 
quence, is increased. The residual matter with which the 
clothing is coated is brought in contact with the skin, which 
causes irritation, and not unfrequently re-absorption of the 
elements, thrown off from the system through this avenue. 
Hence warmth, cleanliness, and health require that the 
clothing, particularly the garments worn next to the skin, 
should be frequently and thoroughly washed. This should 
not be forgotten in regard to children, for their blood circu- 

678. "Why do those parts of the skin usually clothed need protection ? 
679. Why should the apparel be kept clean ? 680. "What effect has un- 
cleanliness upon the porosity of clothing ? What is said in reference to 
the clothinsr of children r 



HYGIENE OF THE SKIN. 309 

lates with greater rapidity than that of .adults, and a propor- 
tionately greater amount of waste matter is thrown off from 
their systems. 

681. The under -garments room during the day should not 
he worn at night, or the reverse. When under-garments are 
worn several successive days or nights, they should not be put 
in drawers, or hung up in a close closet, as soon as taken from 
the body, but should be exposed to a current of air. 

682. Occupied beds should be thoroughly aired in the 
morning. The excretions from the skin are most abundant 
during the hours of sleep ; and if the sheets and blankets, 
together with the bed, are not aired every morning, by being 
so arranged that both surfaces may be exposed to the air, the 
materials eliminated from the skin will be retained in the 
meshes of the bed-clothing, and may be conveyed into the 
system of the next occupant, by absorption. Oftentimes 
diseases of a disagreeable nature are contracted in this way. 
This fact should be instilled into every mother's and daugh- 
ter's mind. 

Observation. Bed-linen should not be put on a bed when 
it is not sufficiently dried, or contains moisture from the excre- 
tions of the skin, nor should beds or bedding be slept in, that 
have remained in a damp room that has not been occupied for 
many weeks, unless the dampness is removed from the bed- 
linen by a warming-pan, or in some other way. 

683. Changes of dress, from thick to thin, should always 
be made in the morning. At this time the vital powers are 
usually in full play. Many a young lady has laid the founda- 
tion of a fatal disease, by disregarding this rule, in exchan- 
ging the thick dress, with woollen stockings, for the flimsy 
dress and hose of silk or cotton, which are considered suitable 



681. Should the garments worn during the day be worn at night ? 
682. What is said respecting the cleanliness of beds and bedding ? 
Why should not bed-linen that is damp be slept in ? 683. When should 
change of dress from thick to thin be made ? Why ? 



310 ANATOMY, PHYSIOLOGY, AND HYGIENE. 

for the ball-room or party. Sudden changes in wearing- 
apparel, as well as in food and general habits, are attended 
with hazard ; and this is proportionate to the weakness or 
exhaustion of the system when the change is made. 

684. When the clothing has become wet, it is best to change 
it immediately. The skin should then be rubbed with a dry 
crash towel, until reaction, indicated by redness, is produced. 
If the garments are not changed, the person should exercise 
moderately, so that sufficient heat may continue to be gener- 
ated in the system to dry the clothing and skin without, a chill. 
Sitting in a cool shade, or current of air, should, by all means, 
be avoided ; as colds are not contracted by free and excessive 
exercise, but by injudicious management after such exercise. 

Observation. When an individual has been thrown into a 
profuse perspiration by violent exercise, though the skin and 
clothing may become wet, he feels no inconvenience from the 
dampness, as long as he continues that amount of exercise ; 
for the reason that the circulation of the blood being increased, 
heat is generated in sufficient quantity to replace the amount 
abstracted from the system in evaporating the free perspira- 
tion ; but as soon as the exercise is discontinued, the increased 
circulation subsides, and with it the extra amount of gener- 
ated heat. This accounts for the chill we experience, when 
the damp clothing is permitted to dry on the body, after the 
cessation of exercise. 

684. "What suggestion when the clothing has become wet ? What should 
be done if the garments are not changed ? "What causes the chill that is 
experienced when damp clothing is permitted to dry on the body ? 



HYGIENE OF THE SKIN. 311 



CHAPTER XXXI V . 

HYGIENE OF THE SKIN, CONTINUED. 

685. Bathing, its necessity and expediency, is obvious 
from the structure and the functions of the skin. The cuticle 
is cast ofF in minute, powdery scales, many of which are 
retained upon the surface by the pressure of clothing. These 
mingle with the oily and saline products of the skin, and form 
a thin crust. This crust, on account of its adhesiveness, 
collects particles of dust and soot from the atmosphere, and 
particles of foreign matter from our dress ; so that in the 
course of the day the whole body becomes coated with im- 
purities. If this coating remains, becomes thick and estab- 
lished upon the skin, it will produce the following effects : — 

686. 1st. The pores will be obstructed, consequently trans- 
piration impeded, and the influence of the skin as an excre- 
tory entirely prevented. When the pores are obstructed, and 
transpiration is checked, the elements of the transpired fluids 
will necessarily be retained in the system ; and, as they are 
injurious and poisonous if retained, they must be removed by 
those organs whose functions in the animal economy are sim- 
ilar, as the lungs, kidneys, liver, intestines, &c. 

687. When these organs are called upon to perform their 
offices, and in addition that of another, the healthy equilibrium 
is destroyed, and the oppressed organ will suffer from exhaus- 
tion, and become the prey of disease. Thus, obviously, habits 
of uncleanliness are a cause of consumption and other seri- 

685. Show the necessity for bathing. 686. What effect upon the body 
if the pores of the skin are obstructed ? 687. What is the effect when an 
organ not only performs its own specific function, but that of another ? 



312 ANATOMY, PHYSIOLOGY, AND HYGIENE. 

ous diseases of the vital organs. Again, obstruction of the 
pores will prevent respiration through the skin, thus depriving 
the blood of one source of its oxygen, and one outlet of its 
carbonic acid, which will diminish the temperature of the 
system, and the same results follow as when the clothing is 
inadequate. 

688. 2d. The retained perspirable matter will irritate the 
skin, both mechanically and chemically ; and this membrane 
will be kept damp and cold, from attraction and detention of 
moisture ; and foreign material, as before adverted to, once 
removed from the system, may be reconveyed into it by ab- 
sorption. As a consequence, cutaneous eruptions and diseases 
will be produced, and the re-absorption of matter once sepa- 
rated from the system, will be the exciting cause of other 
injurious disorders. 

689. 3d. A film of foreign substance on the skin will 
inevitably become the seat of detention of miasmata and 
infectious vapors. These will remain until absorbed, and 
engender the diseases of which they are the peculiar cause. 
This is one reason why filthy persons contract infectious 
diseases more frequently than individuals of cleanly habits. 

690. Bathing is useful to promote cleanliness. In this 
capacity,- it enables us to remove the coating of impurities 
from the exterior of our persons. It effects this purpose by 
dissolving saline matters, and holding in temporary suspen- 
sion those substances which are insoluble. 

691. The cuticle is composed of a substance resembling 
the dried white of egg, or, in a word, albumen. This is solu- 
ble in alkalies, and these are the agents which are commonly 
employed for purifying the skin. Soap is a compound of the 
alkali soda with oil, the former being in excess. When used 

688. How are cutaneous eruptions frequently produced ? 689. How 
are infectious vapors transmitted to the system ? 690. How does bath- 
ing promote cleanliness ? 691. Why is it necessary to use soap in 
bathing ? 



HYGIENE OF THE SKIN. 313 

for washing, the excess of alkali combining with the oily fluid, 
with which the skin is naturally bedewed, removes it, in the 
form of an emulsion, and with it a portion of any adhering 
matter. Another portion of the alkali softens and dissolves 
the superficial layer of the cuticle ; and when this is removed, 
the cuticle is free from impurities. 

692. Every washing of the skin with soap removes the 
old face of the cuticle, and leaves a new one ; and were 
the process repeated to excess, the latter would become so 
thin as to render the body sensible to impressions too slight 
to be felt through its ordinary thickness. On the other hand, 
when the cuticle and its accumulated impurities are rarely 
disturbed, the sensitiveness of the skin is impaired. The 
proper inference to be drawn from the preceding remarks, is 
in favor of the moderate use of soap to cleanse the skin. 

Observatio7i. If any unpleasant sensations are felt after the 
use of soap, they ma}*- be immediately removed by washing the 
surface with water slightly acidulated with lemon-juice or 
vinegar, which neutralizes the alkali that may remain on 
the skin. This is effective treatment for " chapped hands." 

693. Bathing may be partial or general, and the water 
used may be cold, temperate, tepid, warm, or hot. A person 
may apply it to his system with a sponge, it may be poured 
upon him, or he may immerse himself in it. The simplest 
mode of bathing is to apply water to a small extent of sur- 
face, by means of a wet sponge, and after being wiped dry, 
again cover with the dress. In this way the whole body may 
be speedily subjected to the influence of water, and to no less 
useful friction. The water used may be warm or cold. This 
species of bathing may be practised by any invalid, and 

692. Why should only a moderate amount of soap be used in bathing ? 
If unpleasant sensations are felt from too free use of soap, how can they 
be counteracted ? 693. Give the different forms of bathing. What is the 
simplest mode of bathing ? Can this mode be adopted by invalids with 
safety ? 

27 



314 ANATOMY, PHYSIOLOGY, AND HYGIENE. 

always with benefit, if the bathing is succeeded by a glow of 
warmth over the surface ; and this is the test by which the 
benefit of all forms of bathing is to be estimated. 

694. When the heat of the system is adequate, the bather 
may stand or sit in a shallow tub, while he receives the water 
from a sponge squeezed over the shoulders or against the 
body. In this form of bathing, the person is more exposed to 
the cold air, and on this account it is less suitable for very 
feeble individuals than the first-mentioned method. In the 
early use of this form of the sponge-bath, the bather should 
content himself with a single affusion from the sponge ; the 
body should be quickly wiped with a soft towel, and friction 
applied with a crash towel or a brush. 

695. The third kind of bathing is that of the shower-bath, 
which provides a greater amount of affusion than the former, 
combined with a greater shock to the nervous system. The 
concussion of the skin by the fall of water, particularly dis- 
tinguishes this from the previous modes of bathing. The 
degree of concussion is modified by the size of the openings 
through which the water issues, and the height of the reser- 
voir. The shower-bath admits of modification, adapting it to 
the most delicate as well as the robust. The extent of fall, 
the size of the apertures, the quantity and temperature of the 
water, may be regulated at pleasure. 

Observation. In using the shower-bath, it would be judi- 
cious to commence with warm or tepid water, for which, by a 
gradual process, cold water may be substituted. In this way 
the system may be Inured to cold water. After bathing, the 
skin should be wiped dry and rubbed briskly. 

696. The fourth form of bathing is that in which the body, 
or a portion of it, is immersed in water. The temperature 

"What is the test by which to estimate the benefit of all modes of bath- 
ing ? 694. Give another method of sponge-bathing. 695. What is said 
of the shower-bath ? What caution is given ? 696. Give the fourth form 
of bathing. 



HYGIENE OF THE SKIN. 315 

of the water in this form of bathing may be modified accord- 
ing to the sensations and purposes of the bather. This form 
of bathing is designated according to the heat of the water. 
When the temperature is below 75°, it is termed a cold bath ; 
when from 75° to 85°, a temperate bath ; from 85° to 95°, a 
tepid bath; from 95° to 98°, a warm bath ; from 98° to 105°, 
a hot bath. In using this form of bathing, the skin should 
be wiped perfectly dry, and briskly rubbed. 

Observation. The length of time a person may remain in 
a cold bath with benefit varies from two to ten minutes ; 
while a person may remain in a temperate, tepid, or warm 
bath, from ten to thirty minutes, or until special indications 
are exhibited. 

697. In the vapor-bath, the vapor is not only applied to the 
exterior of the system, but it is inhaled and brought in con- 
tact with every part of the interior of the lungs. The bather 
is seated upon a chair, and the vapor gradually turned on 
around him, until the proper temperature (90° to 110°) is 
attained. The bath may be continued from ten to thirty 
minutes. After leaving the bath, attention should be given to 
the skin, as in other forms of bathing. 

698. In order to increase and promote reaction of the skin, 
various measures and processes are used, some of which 
are practised in, and others after, quitting the bath. Of the 
former, the rubbing and brushing the skin are the most com- 
mon and important. The brisk and efficient friction of the 
skin with a coarse towel and flesh-brush, after quitting the 
bath, should never be omitted. This short catalogue embraces 
all the appliances requisite for the purpose. 

699. Bathing promotes health by its immediate and remote 

What degree of temperature of water is termed a cold bath ? A tem- 
perate? A tepid? A warm? A hot bath? State the length of time 
that a person should remain in the different baths. 697. "What is said of 
the vapor bath ? 698. Mention the different methods for promoting reac- 
tion of the skin. 



316 ANATOMY, PHYSIOLOGY, AND HYGIENE. 

physiological effects on the system. When the body is moist- 
ened with a sponge wet with cold water, or when an affusion 
by the sponge or shower-bath is used, the skin instantly 
shrinks, and the whole of its tissue contracts. This con- 
traction diminishes the capacity of the cutaneous system of 
blood-vessels, and a portion of the blood circulating through 
them is suddenly thrown upon the more internal parts of the 
body. The nervous system, among others, participates in it, 
and is stimulated by the afflux, and communicates its stimulus 
to the whole system. This causes a more energetic action of 
the heart and blood-vessels, and a consequent rush of blood 
back to the skin. This is the state termed reaction, the first 
object and purpose of every form of bathing. 

700. This condition of the skin is known by the redness 
of the surface, the glow, comfort, and warmth which follow 
the bath. The bather should direct all his care to insure 
this effect. By it the internal organs are relieved, respiration 
is lightened, the heart is made to beat calm and free, the mind 
is clear and strong, the tone of the muscular system is in- 
creased, the appetite is sharpened, and the whole system feels 
invigorated. This is the end and aim of the bather, and to 
this all his training tends. The error is, to expect the result 
without the preparation. 

701. In order to promote reaction, and to be efficient in 
preserving health, bathing should be regular, should be com- 
menced by degrees, and increased by a process of training, 
and should not be permitted to intrude upon hours devoted to 
some important function, as digestion. It must not precede 
or follow too closely a meal, or severe mental or muscular 
exercise, as reaction is less certain and vigorous when im- 



699. "What is the effect upon the skin when cold water is applied? 
"What is the first object and purpose of every form of bathing ? 700. How 
is this condition of the skin known ? Mention the salutary effects that this 
condition has on the body. 701. How should bathing be performed, in 
order to be efficient in preserving health ? 



HYGIENE OF THE SKIN. 317 

portant internal organs are employed, than when they are at 
rest. When the vital powers are greatest, and the system 
most free from exhaustion, bathing is most beneficial ; hence 
the morning is preferable to the evening, and the middle of 
the forenoon to the middle of the afternoon, for this healthful 
and agreeable duty ; as the vital action of the system is most 
energetic in the early part of the day. 

702. In regard to the frequency of bathing, the face and 
neck, from their necessary exposure to the atmosphere, and 
the impurities which the latter contains, should receive at 
least two washings in twenty-four hours, one of which should 
b° with soap ; the feet, from the confined nature of the cover- 
ings which are worn over them, require at least one ; the 
8"mpits, from the detention, as well as from the peculiar 
p-operties of the secretions, at least one ; and the hands and 
9 v ms, as many as seem proper. The whole person should be 
bathed at least every second day, but the most .perfect health 
of every part of the body would be maintained, if the excre- 
tions from the skin were removed daily. 

703. In diseases of the skin and internal organs, bathing 
is a remedial measure of great power. It should never be 
neglected or omitted. It is not only pleasant and safe, but is 
really more effective than any medicine administered inter- 
nally. This, like other curative means, should be applied by 
the direction and under the eye of the medical adviser, that 
it may be adapted to the condition of the patient. 

704. u From the first hour of man's existence to his latest 
breath, in health and in sickness, rich or poor, water is always 
requisite. Baths were dedicated by the ancients to the divini- 
ties of medicine, strength, and wisdom, namely, iEsculapius, 
Hercules, and Minerva, to whom might properly be added the 
goddess of health, Hygeia. The use of water has been 

When should bathing be performed ? 702. How often should we bathe ? 
703. What is said of bathing in disease ? Who should direct the kind of 
bath proper in different diseases ? 704. Were baths dedicated by the 
ancients ? ^ # 



318 ANATOMY, PHYSIOLOGY, AND HYGIENE. 

enforced as a religious observance, and water has been adopted 
as one of the symbols of Christianity." 

705. The air is an agent of importance in the functions of 
the skin. It imparts to this membrane oxygen, and receives 
from it carbonic acid. It likewise removes from it a large 
portion of the perspiration and the more fluid portions of the 
oily secretion. In order that the air may accomplish these 
ends, it is necessary that it come in contact with the body. 
This is one of the many reasons why we should wear loose 
and porous clothing. 

706. Again, the air should be pure, and free from redun- 
dant moisture. In the warm mornings of July and August, 
the air is loaded with moisture and impurities, and the perspi- 
rable matter is not removed from the system as it is when the 
air is pure and dry. This is the cause of the general lassitude 
that is experienced during such mornings. As soon as the 
fog is dispelled, these unpleasant sensations are removed. To 
sustain the functions of the skin in a healthy state, the parlor, 
kitchen, sleeping-room, school-house, and work-shop, should 
be well ventilated. The blood of the system will be purer, 
and its color of a brighter scarlet, if the skin is surrounded 
by fresh and pure air, than when it is foul or moist. 

707. The light permeating the skin, not only exercises a 
salutary influence upon this membrane, but upon the blood, 
and, through this fluid, upon the whole system. For this 
reason, the kitchen and the sitting-room, which are the apart- 
ments most used by ladies, should be selected from the most 
pleasant and well-lighted rooms in the house. On the other 
hand, dark rooms and damp cellar-kitchens should be avoided, 
as exercising an injurious influence upon both body and mind. 

708. The dark, damp rooms, so much used in cities and 

705. Give the reasons why pure air should be supplied to the skin. 
706. What is the cause of the general lassitude in a damp, warm morn- 
ing ? 707. Show the salutary effects of light on the skin. 708. What is 
one cause of disease and suffering in large villages ? 



HYGIENE OF THE SKIN. 319 

large villages, by indigent families and domestics, are fruitful 
causes of disease, as well as of vice, poverty, and suffering. 
Common observation shows that solar light also exercises much 
influence upon the vigor and color of vegetables. Plants 
that are kept in well-lighted rooms, have darker and more 
brilliant colors than those that grow in darkened apartments. 

709. Burns and scalds are terms applied to those condi- 
tions of the skin which are produced by the application of 
an undue amount of heat, which changes the action of its 
vessels. 

710. A small degree of heat will irritate the nerves, and 
cause an increased action of the blood-vessels. This is 
attended with severe smarting pain, and will be followed by 
the deposition of serum under the cuticle, unless applications 
are made immediately, to prevent vesication, or blistering. 
To prevent or suppress this state of arterial action, wet some 
folds of cotton or woollen cloth with cold water, and apply 
them to the parts scalded ; continue to apply cold water, so as 
to steadily maintain the low temperature of the applications, 
as long as the smarting pain is experienced. The steady 
application of cold dressing also tends to prevent an increased 
action of the blood-vessels, and will suppress it, if it already 
exist. 

711. When blisters are formed, the cuticle is separated 
from the other tissues of the skin by the effusion of serum. 
In all cases, if this layer of the skin is not removed, a small 
opening should be made in the raised cuticle, by which 
the serum deposited may be removed. Under such circum- 
stances, never remove the cuticle, as it makes the best possi- 
ble covering for the blood-vessels and nerves of the true skin. 
The cold water dressing, recommended in the preceding 

709. To what condition of the skin are the terms burns and scalds applied ? 
710. What is the effect when only a small degree of heat is applied to the 
skin ? How can vesication be prevented ? 711. What should be the treat- 
ment when blisters are formed ? 



320 ANATOMY, PHYSIOLOGY, AND HYGIENE. 

paragraph, may then be applied as long as the smarting sensa- 
tion continues. After the pain has subsided, the blistered part 
may be covered by a patch of cotton or linen cloth, upon 
which an ointment, made of lard and bees-wax, has been 
spread. 

712. If the cuticle has been removed, there will be much 
suffering, because the nerves are unduly stimulated by the 
air. The cuticle is the sheath or covering of the vessels 
and nerves of the skin, and when it is removed, a substitute 
should be applied. This substitute should be soothing, and 
cover the denuded surface. Linseed-meal or ground slippery- 
elm bark poultice, fresh cream, or lard and bees-wax, spread 
upon linen or cotton cloth, would make a good dressing. 
When dressings are applied, they should not be removed until 
they become dry and irritating. 

713. If there is much suffering, administer to an adult from 
twenty-five to sixty drops of laudanum, according to the 
severity of the pain. If the patient is a child, from fifteen 
drops to a tea-spoonful of paregoric may be administered. 
When there is much prostration, some hot peppermint tea or 
other stimulant may be found necessary to bring on reaction. 

714. The hands, feet, ears, &c, are subject, in cold lati- 
tudes, to he frozen, or frost-bitten. This may occur when the 
patient, at the moment, is not aware of it. The part affected 
at first assumes a dull red color, which gradually gives place 
to a pale, waxy appearance, and becomes quite insensible. 
The first thing to be done in such cases, is to reestablish cir- 
culation. This should be effected very gradually. If a large 
quantity of blood is thrown suddenly into the chilled and 
debilitated vessels of the frozen part, inflammation may be 
produced that will destroy the vitality of the limb. 

712. "What should be the treatment if the cuticle has been removed ? 
How often should the dressing of burns be removed ? 713. What may be 
necessary when there is much suffering? 714. What is the appearance of 
limbs while freezing ? How should the circulation be at first reestablished ? 
What should be avoided ? 



HYGIENE OF THE SKIN. 321 

715. The circulation and sensibility may be restored by 
rubbing the frozen limb, with snow, or, when this is not to be 
obtained, cold water ; but snow is always to be preferred. 
The fire should be avoided ; and it would be better for the 
patient to be kept in a cold room, for a time, where there is 
no fire, or where the temperature is moderate. 

716. When a person is found benumbed with cold, and 
almost or quite insensible, he should be taken into a cold room, 
the clothing removed, and friction commenced and continued 
for some time, with snow. When warmth begins to be 
restored, the individual should be rubbed with dry flannel, and 
the friction continued until reaction takes place. 

Observation. When the toes and heels have been repeat- 
edly chilled, there may be produced a disease called chil- 
blains. This affection is attended with tenderness of the parts, 
accompanied with a peculiar and troublesome itching. The 
prevention of this disease is in wearing warm hose and thick 
shoes of ample size. Bathing the feet morning and evening 
is also a prevention of this disagreeable affection. When 
chilblains exist, apply cold water, warm camphorated spirits, 
or turpentine linament. 

715. How may the circulation and sensibility be restored ? 716. "What 
treatment should be adopted when a person is benumbed with cold ? What 
treatment should be adopted when warmth begins to be restored ? What 
is said of chilblains ? 



322 ANATOMY, PHYSIOLOGY, AND HYGIENE. 



CHAPTER XXXV. 

APPENDAGES OE THE SKIN. 

717. The hairs are appendages of the skin, and, like 
the cuticle, they are a product of secretion. They have no 
blood-vessels or nerves, and, consequently, no vitality. The 
hairs take their origin from the cellular membrane, in the 
form of bulbs. Each hair is enclosed beneath the surface 
by a vascular secretory follicle, which regulates its form dur- 
ing growth. In texture, it is dense, and homogeneous toward 
the circumference, and porous and cellular in the centre, like 
the pith of a plant. Every hair has on its surface pointed 
barbs, arranged in a spiral manner, and directed toward the 
root of the hair ; so that, if a hair be rolled between the fin- 
gers, it moves only in one direction. 

Fig. 118. 




5 

Fig. 118. The hair follicle (1) is represented as imbedded in the cellular membrane, 
(2,) which is situated beneath the skin. 3, 3, The membranous sac, which has a 
narrow neck, opening externally by a contracted orifice, through which the hair (4; 
passes. Its internal surface is smooth, and not adherent to the hair, but separated from 
it by a reddish fluid. From the bottom of the sac (5) the pulp of the hair arises, and 
passes through the skin at 6. 

717 — 723. Describe the appendages of the skin. 717. "Why have not hairs 
vitality ? Where do they take their origin ? Give their structure. "What 
is represented by fig. 118 ? 



APPENDAGES OF THE SKIN. 323 

718. The color of the hair varies in different individuals, 
and is generally supposed to depend on the fluids contained 
in the pith. There are two causes which act in changing 
the hair gray. The first is, defective secretion of the color- 
ing fluid. The second is, the canals, which convey the fluid 
into the hair, become obliterated. In the first instance, the 
hair will remain ; in the second, it dies, and drops out ; the 
cuticle of the scalp grows over the canal, which is soon oblit- 
erated, and the head becomes bald. 

Observation. It is related that the hair of Marie Antoinette, 
Queen of France, and others, from excessive mental agita- 
tion, changed from black to gray in a single night. This is 
not strictly true ; the secretion may be arrested, but that 
already deposited in the pith will require days or weeks to be 
removed. 

719. Upon the upper part of the head, the oil-tubes open 
into the hair-sacs ; consequently, the secretion of the oil- 
glands is spread over the surface of the hair, and not upon 
the cuticle. This is the cause of the dry, white, branny 
scales, called " scurf," or " dandruff," upon the head. This 
is natural, and cannot be prevented. When scurf exists, the 
only necessary application to remove it, is the frequent use 
of the hair-brush, and washing with pure water. 

Observation. The secretion of the oil-glands may become 
impacted around the hairs as they issue from the skin, and 
thus prevent their outward movement in growing. The 
pressure of the matter deposited at their bulbs will then cause 
itching. The comb and the brush may be used to remove the 
impacted matter, and relieve the disagreeable sensation. 

720. The oil is most abundant near the roots of the hair. 



718. Upon what does the color of the hair depend ? "What are the causes 
of the hair becoming gray ? What is the cause of the hair dropping out ? 
What is related of Marie Antoinette? 719. How is "dandruff" on the 
scalp produced? What is the only necessary application to remove it ? 
Give observation. 720. Where is the oil of the hair most abundant ? 



324 ANATOMY, PHYSIOLOGY, AND HYGIENE. 

A free use of the brush spreads it along the hairs, and gives 
them a smooth, glossy appearance. Soap should rarely be 
used in washing the head, as it will remove the oil which is 
essential to the health and appearance of the hair. 

721. The uses of the hair vary in different regions of the 
body. Upon the head, it aids in shielding the brain from 
injury by blows, and it likewise serves to protect this part 
of the system from heat and cold, thus maintaining equal 
temperature of the cerebral organ. About the flections of the 
joints, as in the axilla, (armpit,) they prevent irritation of the 
skin from friction ; in the passages to the ears and nostrils, they 
present an obstacle to the ingress of insects and foreign bodies ; 
while in the eyebrows and eyelids, they serve to protect the 
organ of vision. 

Fig. 119. 




Fig. 119. A section of the end of the finger and nail. 4, Section of the last bone 
of the finger. 5, Fat, forming the cushion at the end of the finger. 2, The nail. 
1, 1, The cuticle continued under and around the root of the nail, at 3, 3, 3. 

722. The nails are hard, elastic, flexible, semi-transparent 
scales, and present the appearance of a layer of horn. The 
nail is divided into the root, the body, and the free portion. 
The root is that part which is covered on both surfaces ; the 
body is that portion which has one surface free ; the free por- 
tion projects beyond the end of the finger. 

723. The nail is formed of several laminae, or plates, that 
are fitted the one to the other ; the deepest is that which is 
last formed. The nails, as well as the hoofs of animals and 

How can it be spread along tne hairs ? Why should soap not be used 
in washing the hair ? 721. Of what use is the hair upon the head ? About 
the flexions of the joints ? In the nasal and ear passages ? Upon the eye- 
brows and eyelids ? 722. Describe the nails. 723. How are they formed ? 



APPENDAGES OF THE SKIN. 325 

the cuticle, are products of secretion. They receive no blood- 
vessels or nerves. If the cuticle be removed in severe scalds, 
they will separate with it, as the hoofs of animals are removed 
by the agency of hot water. The nails increase in length 
and thickness, by the deposition of albumen upon their under 
surface, and at their roots, in a manner similar to the growth 
of the cuticle, of which they constitute a part. 

Observations. 1st. The nail upon its under surface is fash- 
ioned into thin vertical plates, which are received between the 
folds of the sensitive skin. In this manner, the two kinds of 
laminae reciprocally embrace each other, and the firmness of 
connection of the nail is maintained. If we look on the sur- 
face of the nail, we see an indication of this structure in the 
alternate red and white lines which are there observed. The 
former of these correspond with the sensitive laminae ; the lat- 
ter with the horny plates. The ribbed appearance of the nail 
is due to the same circumstance. These sensitive laminae are 
provided with an unusual number of capillary vessels for the 
formation of the nail, and hence they give a red tint to the 
portion under which they lie. 

2d. Near the root of the nail there is a part that is not 
laminated, and it is less abundantly supplied with blood-vessels. 
This portion consequently looks pale compared with the lam- 
inated portion, and from its half-moon shape is technically 
termed lunula. Beyond the lunula, the root of the nail is 
imbedded in the fold of the sensitive skin, and has the same 
relation to that structure that any single one of the thin horny 
plates of its under surface has to its corresponding pair of sen- 
sitive laminae. . 

724. The nails, from their position, are continually receiv- 
ing knocks, which produce a momentary disturbance of their 
cell formation, followed by a white spot. The care of the 
nails should be strictly limited to the knife or scissors, to 

Give observation 1st. Observation 2d. 724. How should the nails be 
treated to prevent irregularities and disease ? 
28 



326 ANATOMY, PHYSIOLOGY, AND HYGIENE. 

their free border, and an ivory presser, to prevent adhesion 
of the free margin of the scarf-skin to the surface of the 
nail. This edge of the cuticle should never be pared, the 
surface of the nail never scraped, nor the nails cleaned with 
any instrument whatever, except the nail-brush, aided by 
water and soap. An observance of these suggestions, will 
prevent irregularities and disorders of the nails. 

Observations. 1st. When we wear a shoe that is too short 
for the foot, the edge of the nail is brought against the leather. 
This interrupts the forward growth of the nail, and it spreads 
out on the sides, and becomes unusually thick. It then presses 
upon the soft parts, and is said to " grow into the flesh." The 
prevention is, to wear shoes of ample size. 

2d. Instances are by no means unfrequent in which the 
power of production of the nail at the root becomes entirely 
destroyed, and it then grows in thickness only. When this 
affection occurs, it is often remarkable what a mass the nail 
presents. Instances are on record, where the nail is regularly 
shed ; and, whenever the old nail falls off, a new one is found 
beneath it, perfectly formed. Sometimes the growth in length 
is not entirely checked, although growth in thickness is in- 
duced ; the nail then presents a peculiar appearance. 



What causes the edge of the nail " to grow into the flesh" of the toe ? 
How prevented ? 



ANATOMY OF THE NERVOUS SYSTEM. 327 



CHAPTER XXXVI. 

THE NERVOUS SYSTEM. 

725. In the preceding chapters, we have seen how various 
and complex are many of the motions necessary to maintain 
the life of an animal whose organization is superior to all 
others. We have noted the wonderful mechanism of the 
muscular system, in producing the varied movements of the 
body, the different processes by which the food is converted 
into chyle and mixed with the blood, and the circulation of 
this fluid to every organ and tissue of the system, that each 
may select from it the very principles which it requires for 
its growth. 

726. Lymphatic absorption commences, as soon as nutri- 
tion is completed, and conveys the useless, worn-out particles 
of different tissues back into the circulating fluid ; while the 
respiratory organs and secretory glands perform the work 
of preparing the waste products to be eliminated from the 
body. Each of these processes effects a single object, and is 
performed in a regular manner. 

727. " They must succeed each other in proper order in 
propelling every particle to its proper destination, or life 
would be sacrificed almost at the moment of its commence- 
ment. There is, therefore, a mutual dependence of all portions 
of the machinery of organic life upon each other, and a neces- 
sity for some medium of communication from one organ to 
another, by which they may convey mutual information of 

725. What has been noted in the preceding chapters ? 726. Show the 
manner in which the several processes are performed. 727. How must 
they succeed each other ? 



328 ANATOMY, FHYSIOLOGY, AND HYGIENE. 

their several conditions, if we may be permitted to employ a 
figurative expression. Were there no such medium, how 
would the stomach notify the heart that additional exertion on 
its part is required, because the stomach is busy in digesting 
food ? 

728. " When we are exerting the muscular system for a 
long time in some laborious employment, how else are our 
members to inform the stomach that they are too much occu- 
pied with their duties to spare the blood necessary in diges- 
tion ; that it is requisite that the appetite should decline ; and 
that digestion should cease for the time, even if the stomach 
should be oppressed with its contents ? When we are think- 
ing, how else are the blood-vessels to be told that an unusual 
supply of their contents is wanting in the head ? or when the 
whole frame is weary with exertion, how, without some regular 
line of intelligence between all the organs, is the brain to be 
instructed that circumstances require that it should go to 
sleep ? To supply the necessary medium of communica- 
tion, Providence has furnished all the animals that possess 
distinct organs, with a peculiar apparatus called the Nervous 
System." 

ANATOMY OF THE NERVOUS SYSTEM. 

729. The nervous system consists of the Cer'e-hro-spi'nal 
Cen'tre, and of numerous rounded and flattened white cords, 
called nerves, which are connected at one extremity with the 
cerebro-spinal centre, and at the other, distributed to all the 
textures of the body. The sympathetic nerve is an exception 
to this description ; for, instead of one, it has many small 
centres, which are called gan'gli-a, and which communicate 
very freely with the cerebro-spinal centre, and with its 



728. What is the medium of communication from one organ to another ? 
729 — 754. Give the anatomy of the brain and cranial nerves. 729. Of what 
does the nervous system consist ? "What constitutes an exception to this ? 



ANATOMY OF THE NERVOUS SYSTEM. 



329 



730. The cerebro-spinal centre consists of two portions : 
The brain, and the spinal cord. For convenience of de- 
scription, the nervous system may be divided into the Brain, 
Cranial Nerves, Spinal Cord, Spinal Nerves, and the Sym- 
pathetic Nerve. 

731. The term brain designates those parts of the nervous 
system, exclusive of the nerves themselves, which are con- 
tained within the cranium, or skull-bones ; they are the Cer'e- 
brum, Cer-e-bel'lum, and Me-duVla Ob-lon-ga'ta. These are 
invested and protected by the membranes of the brain, which 
are called the Du'ra Ma'ter, A-rach'noid, and Pi'a Ma'ter. 

Fig. 120. 




Fig. 120. 1. 1, The scalp turned down. 2, 2, 2, The cut edge of the bones of the 
skull. 3, The external strong membrane of the brain (dura mater,) suspended by a 
hook. 4, The left hemisphere of the brain, showing its convolutions. 



730. Of what does the cerebro-spinal centre consist ? How is the nervous 
system divided ? 731. What does the term brain designate ? Name them. 
How are they protected ? Describe fig. 120. 
28* 



330 



ANATOMY, PHYSIOLOGY, AND HYGIENE. 



732. The cerebrum is divided into two hemispheres, by a 
cleft, or fissure. Into this cleft dips a portion of the dura 
mater, called the falx cer'e-bri, from its resembling a sickle. 
The apparent design of this membrane is to relieve the one 
side from the pressure of the other, when the head is reclin- 
ing to either side. Upon the superior surface of the cere- 
brum are seen undulating windings, called con-vo-lu'tions. 
Upon its inferior, or lower surface, each hemisphere admits 
of a division into three lobes — the anterior, middle, and 
posterior. 

Fig. 121. 




Fig. 121. A section of the skull-bones and cerebrum. 1, 1, The skull. 2, 2, The 

dura mater. 3, 3, The- cineritious portion of the cerebrum. 4, 4, The medullary 

portion. The dark points indicate the position of divided blood-vessels. 5, 5, The 
lateral ventricles. 



732. How is the cerebrum divided ? "What is the use of the falx cerebri ? 
What is seen upon the superior surface of the brain ? Its inferior ? 



ANATOMY OF THE NERVOUS SYSTEM. 331 

733. When the upper part of the hemispheres is removed 
horizontally with a sharp knife, a centre of white substance is 
brought to view. This is surrounded by a border of gray, 
which follows the depressions of the convolutions, and pre- 
sents a zigzag outline. The divided surface will be seen 
studded with numerous small red points, which are produced 
by the escape of blood from the division of the minute arte- 
ries and veins. The gray border is called the cortical, or cin- 
eritious portion, while the white central portion is called the 
medullary. The two hemispheres are connected by a dense 
layer of transverse fibres, called cor'pus cal-lo'sum. 

734. In the interior of the brain there are several cavities, 
two of which are of considerable size, and are called the 
lateral ventricles. They extend from the anterior to the pos- 
terior part of the brain, and wind their way into other parts of 
the cerebral organ. 

Observation. In the disease called " dropsy of the brain," 
(hydrocephalus internus,) the serum, or water, is usually de- 
posited in these ventricles. This is effused from the many 
small blood-vessels that are found in these cavities. 

735. The brain is of a pulpy character, quite soft in 
infancy and childhood ; but it gradually becomes more and 
more consistent, and in middle age it assumes the form of 
determinate structure and arrangement. It is more abun- 
dantly supplied with blood than any organ of the system. 
No lymphatics have been detected, but it is to be presumed 
that they exist in this organ. 

736. The cerebellum is about seven times smaller than 
the cerebrum. Like that organ, it is composed of white and 



733. Describe the appearance of the brain when a horizontal section has 
been made. WhaWis the gray border often called ? "What connects the 
hemispheres ? 734. Describe the ventricles of the brain. In the disease 
called "dropsy of the brain," where is the water deposited? 735. What 
is the character of the brain in childhood ? In adults ? 736. How does 
the cerebellum compare in size with the cerebrum ? 



332 



ANATOMY, PHYSIOLOGY, AND HYGIENE. 



gray matter, but the gray constitutes the larger portion. Its 
surface is formed of parallel plates separated by fissures. 
The white matter is so arranged, that when cut vertically, the 
appearance of the trunk and branches of a tree (ar'bor vi'ta) 
is presented. It is situated under the posterior lobe of the 
cerebrum, from which it is separated by a process of the dura 
mater, called the ten-to'ri-um. 

Fig. 122. 




Fig. 122. The under surface, or base, of the brain and origin of the cranial nerves. 
1, 1, The anterior lobes of the cerebrum. 2, 2, The middle lobes. 3, 3, The poste- 
rior lobes, almost concealed by the cerebellum. 4, 4, The cerebellum. 7, 7, The 
longitudinal fissure that divides the brain into two hemispheres. 8, The first pair 
of nerves. 9, 9, The second pair of nerves. 10, The decussation, or crossing, of its 
fibres. 13, 13, The third pair of nerves. 14, The pons varolii. 15, 15, The fourth 
pair of nerves. 16, 16, The fifth pair of nerves. 17, The sixth pair of nerves. 
18, 18, The seventh and eighth pair of nerves. 19, The medjjlla oblongata, with the 
crossing of some of its fibres exhibited. 20, The ninth pairof nerves. 21, The tenth 
pair of nerves. 22, The eleventh pair of nerves. 23, The twelfth pair of nerves. 



Describe this portion of the brain. Explain fig. 122. 



ANATOMY OF THE NERVOUS SYSTEM. 



333 



737. The medulla oblongata, or that portion of the 

spinal cord which is within the skull, consists of three pairs 

of bodies, (cor'pus py-ram-i-ddle, res-ti-for'me, and ol-i-va're,) 

united in a single bulb. 

Fig. 123. 




Fig. 123. The base of the skull and the openings through which the cranial nerves 
pass. 1, 1, The first pair of nerves. 2, 2, The cribriform plate of the ethmoid bone, 
through which this nerve passes. 3, 3, The second pair of nerves. 4, 4, The optic 
foramen in the sphenoid bone ; through which passes the second pair of nerves. 
5, 5, The sphenoidal fissure. 6, 6, The third pair of nerves. 7, 7, The fifth pair of 
nerves. 8,8, The ophthalmic branch of the fifth nerve. The third, the ophthalmic 
branch of the fifth and the sixth nerve pass from the brain through the sphenoidal 
fissure to the eye. 9,9, The superior maxillary branch of the fifth nerve. 10, 10, The 
foramen rotundum, (round opening,) through which the nerve 9, 9, passes to the upper 
jaw. 11, 11, The inferior maxillary branch of the fifth pair. 12, 12, The foramen 
ovale, (oval opening,) through which the nerve 11, 11, passes to the lower jaw. 
13, 13, The sixth pair of nerves. 14, 14, The seventh and eighth pair of nerves. 
15, 15, The opening in the temporal bone, through which the seventh and eighth 
nerves pass to the face and ear. 16, 16, The ninth pair of nerves. 17, The tenth 
pair of nerves. 18, 18, The eleventh pair of nerves. 19, 19, The foramen lacerum 
(rough opening.) The ninth, tenth, and eleventh nerves pass from the brain through 
this opening. 20, The spinal cord. 21, The foramen spinalis, through which the 
spinal cord passes. 22, 22, The position of the anterior lobe of the brain. 23, 23, The 
middle lobe. 24, 24, The posterior lobe. 25, 25, A section of the skull-bones. 

737. Describe the medulla oblongata. Explain fig. 123. 



334 



ANATOMY, PHYSIOLOGY, AND HYGIENE. 



738. The dura mater is a firm, fibrous membrane, which 
is exposed on the removal of a section of the skull-bones. 
This lines the interior of the skull and spinal column, and 
likewise sends processes inward, for the support and protec- 
tion of the different parts of the brain. It also sends pro- 
cesses externally, which form the sheaths for the nerves, as 
they quit the skull and spinal column. The dura mater is 
supplied with arteries and nerves. 

Fig. 124. 




Fig. 124. A vertical section of the cerebrum, cerebellum, and medulla oblongata, 
showing the relation of the cranial nerves at their origin. 1, The cerebrum. 2, The 
cerebellum, with its arbor vitre represented. 3, The medulla oblongata. 4, The spinal 
cord. 5, The corpus callosum. 6, The first pair of nerves. 7, The second pair. 
8, The eye. 9, The third pair of nerves. 10, The fourth pair. 11, The fifth pair. 
12, The sixth pair. 13, The seventh pair. 14, The eighth pair. 15, The ninth pair. 
16, The tenth pair. 19, The eleventh pair. 18, The twelfth pair. 20, Spinal 
nerves. 21, The tentorium. 



738. Describe the dura mater. What is its use ? Explain fig. 124. 



ANATOMY OF THE NERVOUS SYSTEM. 335 

739. The arachnoid, so called from its extreme tenuity, is 
the serous membrane of the brain and spinal cord, and is, like 
other serous membranes, a closed sac. It envelops these 
organs, and is reflected upon the inner surface of the dura 
mater, giving to that membrane its serous investment. 

740. The pia mater is a vascular membrane, composed 
of innumerable vessels, held together by cellular membrane. 
It invests the whole surface of the brain, and dips into its 
convolutions. The pia mater is the nutrient membrane of the 
brain, and receives its blood from the carotid and vertebral 
arteries. Its nerves are minute branches of the sympathetic, 
which accompany the branches of the arteries. 

741. The cranial nerves, that connect with the brain, are 
arranged in twelve pairs. They are called : 1st. The 01- 
fact'o-ry. 2d. The Op'tic. 3d. The Mo-to'res Oc-u-lo'rum. 
4th. The Pa-thet'i-cus. 5th. The Tri-fa'cial. 6th. The 
Ab-du-cen'tes. 7th. The Por'ti-o Bu'ra. 8th. The Por'ti-o 
Mollis. 9th. The Glos'so-pha-ryn'gi-al. 10th. The Pneu- 
mo-gas 1 trie. 11th. The Spi'nal Ac'ces-so-ry. 12th. The 
Hy'po-glos'sal. 

742. The olfactory nerve (first pair) passes from the 
cavity of the skull through many small openings in a plate of 
the eth'moid bone. (This plate is called crib'ri-form, from 
its resemblance to a sieve.) This nerve ramifies upon the 
membrane that lines the nasal passages. It is the softest 
nerve of the body. 

743. The optic nerve (second pair) passes from the inte- 
rior of the cranium, through an opening in the base of the 
skull, (fo-ra'men op'ti-cmn,) to the cavity for the eye. It 
pierces the coats of the eye, and expands in the retina. 

744. The motores oculorum (third pair) pass from the 

739. Describe the arachnoid membrane. 740. "What is said respecting 
the pia mater ? 741. How many pairs of cranial nerves ? Name them. 
742. Describe the olfactory nerve. 743. The optic nerve. 744. Describe the 
motores oculorum. 



336 



ANATOMY, PHYSIOLOGY, AND HYGIENE. 



brain, through an opening of the sphe'noid bone, (sphe-noid'al 
Jis'sure,) to the muscles of the eye. 

745. The patheticus (fourth pair) passes from the brain, 
through the sphenoidal fissure, to the superior oblique muscle 
of the eye. 

Fig. 125. 




Fig. 125. The distribution of the third, fourth, and sixth pairs of nerves, to the 
muscles of the eye. 1, The ball of the eye and rectus externus muscle. 2, The up- 
per jaw. 3, The third pair, distributed to all the muscles of the eye, except the 
superior oblique, and external rectus. 4, The fourth pair passes to the superior 
oblique muscle. 6, The sixth pair, is distributed to the external rectus muscle. 



746. The trifacial nerve (fifth pair) is analogous to the 
spinal nerves in its origin by two roots, from the anterior 
and posterior columns of the spinal cord. It has a ganglion, 
like the spinal nerves upon its posterior root. For these 
reasons, it ranges with the spinal nerves, and is considered 
the cranial spinal nerve. This nerve divides into three 
branches : — The oph-thal'mic, superior max'il-la-ry, and in- 
ferior max'il-la-ry. 

745. The patheticus. What does fig. 125 represent ? 746. What is the 
trifacial nerve sometimes called ? Why is it classed with the cranial 
spinal nerves ? Give the names of its branches. 



ANATOMY OF THE NERVOUS SYSTEM. 



337 



747. The ophthalmic nerve passes from the cranial cavity- 
through the sphenoidal fissure. It sends branches to the fore- 
head, eye, and nose. The superior maxillary nerve passes 
through an opening in the base of the skull, {foramen ro-tun'- 
dum,) and sends branches to the eye, the teeth of the upper 
jaw, and the muscles of the face. The inferior maxillary nerve 
escapes from the cranial cavity through an opening called 
foramen o-va'le. It sends branches to the muscles of the 
lower jaw, the ear, the tongue, and the teeth of the lower jaw. 

Fig. 126. 




Fig. 126. The distribution of the fifth pair of nerves. 1, The orbit for the eye. 
2, The upper jaw. 3, The tongue. 4. The lower jaw. 5, The fifth pair of nerves. 
6, The first branch of this nerve, that passes to the eye. 9, 10, 11, 12, 13, 14, 
Divisions of this branch. 7, The second branch of the fifth pair of nerves is dis- 
tributed to the teeth of the upper jaw. 15, 16, 17, 18, 19, 20, Divisions of this 
branch. 8, The third branch of the fifth pair, that passes to the tongue and teeth of 
the lower jaw. 23, The division of this branch that passes to th a tongue, called the 
gu-t'a-tu-ry. 24. The division that is distributed to the teeth of the lower jaw. 

747. Where do the filaments of the ophthalmic branch ramify ? The 
superior maxillary ? The inferior maxillary ? Explain fig. 126. 

29 



338 



ANATOMY, PHYSIOLOGY, AND HYGIENE. 



748. The abdtjcentes (sixth pair) passes through the open- 
ing by which the carotid artery enters the cranial cavity. 
It is the smallest of the cerebral nerves, and is appropriated 
to the external straight muscle of the eye. 

749. The portio mollis (seventh pair) enters the hard 
portion of the tem'po-ral bone at the internal auditory open- 
ing, and is distributed upon the internal ear. 



Fis. 127. 




Fig. 127. A representation of the distribution of the eighth pair of nerves with 
some branches of the fifth. J, 2, 3, 5, 7, 9, Are branches of the eigbtti pair. They 
are distributed over the face in a radiated manner, which constitutes the pes an- 
serinus, (foot of a goose.) The nerves 4, 6, 8, are branches of the fifth pair. 10, 
11, 12, 13, 14, 15, 16, Are brandies of nerves from the upper part of the spinal cord, 
(cervical.) 

750. The facial nerve (eighth pair) passes from the skull 
through an opening situated below the ear, (mas'toid fora- 
men.) It is distributed over the face, supplying the muscles 
with nervous filaments. 



748. What is said of the abrtueentes, or sixth pair of nerves ? 749. Of 
the portio mollis ? Explain fig. 127. 750. Of the facial nerve ? 



ANATOMY OF THE NERVOUS SYSTEM. 339 

751. The glosso-pharyngeal nerve (ninth pair) passes 
from the brain, through an opening with the jugular vein, (fo- 
ramen lade-rum.) It is distributed to the mucous membrane 
of the tongue and throat, and also to the mucous glands of 
the mouth. 

752. The pneumogastric nerve (tenth pair) escapes from 
the brain through the foramen lacerum. It sends branches 
to the larynx, pharynx, oesophagus, lungs, spleen, pancreas, 
liver, stomach, and intestines. 

753. The spinal accessory nerve (eleventh pair) has its 
origin in the respiratory tract of the spinal cord. It connects 
with the ninth and tenth pairs of nerves, and is distributed to 
the muscles about the neck. 

754. The hypo-glossal nerve (twelfth pair) passes from 
the brain, through a small opening, (con 1 dy -hid foramen.) It 
ramifies upon the muscles of the tongue, and is its motor 
nerve. 

Observation. The cranial nerves, with Jhe exception of the 
olfactory, optic, and auditory, connect with each other by 
means of filaments. They also send connecting nervous fila- 
ments to the upper spinal nerves, (cervical,) and the sympa- 
thetic nerve. 



751. Describe the glosso-pharyngeal nerve. 752. The pneumogastric 
nerve. 753. The spinal accessory nerve. 754. The hypo-glossal nerve. 



340 ANATOMY, PHYSIOLOGY, AND HYGIENE. 



CHAPTER XXXVII. 

ANATOMY OF THE NERVOUS SYSTEM, CONTINUED. 

755. The spinal column contains the spinal cord, the roots 
of the spinal nerves, and the membranes of the cord. 

756. The spinal cord extends from the medulla oblongata 
to the second lumbar vertebra, where it terminates in a round- 
ed point. It presents a difference of diameter in different 
parts of its extent, and exhibits three enlargements. The 
uppermost of these is the medulla oblongata. There is no 
distinct demarkation between this enlargement and the spinal 
cord. The next corresponds with the origin of the nerves 
distributed to the upper extremities ; the third enlargement 
is situated near the termination of the cord, and corresponds 
with the attachment of the nerves which are intended for the 
supply of the lower extremities. 

757. An anterior and posterior fissure divides the spinal 
cord into two lateral cords. These are united by a thin layer 
of white substance. The lateral cords are each divided by 
furrows into three distinct sets of fibres, or columns ; namely, 
the anterior, lateral, and posterior columns. The anterior 
are the motor columns ; the posterior are the columns of sen- 
sation ; the lateral columns are divided in their function be- 
tween motion and sensation. They contain the fasciculus 
described, by Sir Charles Bell, as the respiratory tract. 

755—767. Give the anatomy of the spinal cord, spinal nerves, and the sym- 
pathetic nerve. 755. What does the spinal column contain ? 756. Give the 
extent of the spinal cord. How many enlargements has this cord ? "What 
is said of each enlargement? 757. Into how many parts is the spinal 
cord divided ? Give the function of these columns. 



ANATOMY OF THE NERVOUS SYSTEM. 



341 



758. The spinal nerves, that connect with the spinal 
cord, are arranged in thirty-one pairs, each arising by two 



Fig. 129. 






4 : " x , 











Fig. 128. A section of the brain and spinal column. 1, The cerebrum. 2, Ths 
cerebellum. 3, The medulla oblongata. 4, 4, The spinal cord in its canal. 

Fig. 129. Anterior view of the brain and spinal cord. 1, 1, The two hemispheres 
of the cerebrum. 3, 3, The cerebellum. 4, The olfactory nerve. 5, The optic 
nerve. 7, The third pair of nerves. 8, The pons varolii. 9, The fourth pair of 
nerves. 10, The lower portion of the medulla oblongata. 11, 11, The spinal cord. 
12, 12, Spinal nerves. 13, 13, The brachial plexus. 14, 14, The lumbar and sacral 
plexus. 



758. How many pairs of nerves issue from the spinal cord ? Explain fig: 
123. Fig. 129. 

29* 



342 



ANATOMY, PHYSIOLOGY, AND HYGIENE. 



roots ; an anterior, or motor root, and a posterior, or sensitive 
root. Each nerve, when minutely examined, is found to con- 
sist of an aggregate of very delicate filaments, enclosed in a 
common cellular envelope. 

759. The anterior roots arise from a narrow white line 
upon the anterior columns of the spinal cord. The posterior 
roots arise from a narrow gray band formed by the internal 
gray substance of the cord. They are larger, and the fila- 
ments of origin more numerous than those of the anterior 
roots. A ganglion is found upon each of the posterior roots 
in the openings between the bones of the spinal column through 
which the nerve passes. 

Fig. 130. 




Fig. 130. A section of the spinal cord, surrounded by its sheath. B, A spinal 
nerve, formed by the union of the motor root (C) and the sensitive root (D.) At D, 
the ganglion upon this root is seen. 

760. After the formation of the ganglion, the two roots 
unite, and constitute a spinal nerve, which passes through the 
opening between the vertebras on the sides of the spinal 
column. The nerves divide and subdivide, until their minute 
filaments ramify on the tissues of the different organs. 



759. Give the origin of the anterior roots. Of the posterior roots. In 
what respect do the posterior roots differ from the anterior ? 760. When 
do the two roots unite, and where do they pass ? 



ANATOMY OF THE NERVOUS SYSTEM. 343 

761. The spinal nerves are divided into — 

Cervical, 8 pairs, 

Dorsal, 12 " 

Lumbar, 5 " 

Sacral, 6 " 

762. The four lower cervical and upper dorsal pass into 
each other, and then separate to reunite. This is called the 
brach'i-al plex'us. From this plexus six nerves proceed, 
which ramify upon the muscles and skin of the upper ex- 
tremities. 

763. The last dorsal and the five lumbar nerves form a 
plexus called the lumbar, similar to that of the cervical. Six 
nerves pass from this plexus, which ramify upon the muscles 
and skin of the lower extremities. 

764. The last lumbar and the four upper sacral unite to 
form the sacral plexus. From this plexus five nerves pro- 
ceed, that are distributed to the muscles and skin of the hip 
and lower extremities. 

765. The sympathetic nerve * consists of a series of 
Gan'gli-a, or knots, extending each side of the spinal column, 
forming a chain its whole length. It communicates with both 
the cranial and spinal nerves. With the exception of the 
neck, there is a ganglion for each intervertebral space. These 
ganglia are composed of a mixture of cineritious and medul- 
lary matter, and are supposed to be productive of peculiar 
nervous power. 

* The structure of this nerve is very complicated, and different 
physiologists ascribe to it various functions. The character of its dis- 
eases are not well understood. 

761. Give the division of the spinal nerves. 762. What nerves consti- 
tute the brachial plexus ? How many nerves pass from this plexus ? 
763. How many nerves from the lumbar plexus, and where do they ram- 
ify ? 764. How is the sacral plexus formed ? 765. Of what does the 
sympathetic nerve consist ? How is the sympathetic nerve distributed ? 
"What exception ? Of what are the ganglia composed ? 



344 ANATOMY, PHYSIOLOGY, AND HYGIENE. 

Fi2. 131. 




THF.oor 



ANATOMY OF THE NERVOUS SYSTEM. 345 

766. The ganglia may be considered as distinct centres, 
giving off branches in four directions ; namely, the superior, 
or ascending, to communicate with the ganglion above ; the 
inferior, or descending, to communicate with the ganglion 
below ; the external, to communicate with the spinal nerves ; 
and the internal, to communicate with the sympathetic fila- 
ments. It is generally admitted that the nerves that pass from 
the ganglia are larger than those that entered them ; as if 
they imparted to the nerve some additional power. 

767. The branches of distribution accompany the arteries 
w T hich supply the different organs, and form communications 
around them, which are called plexuses, and take the name 
of the artery with which they are associated. Thus we have 
the mesenteric plexus, hepatic plexus, splenic plexus, &c. All 
the internal organs of the head, neck, and trunk, are supplied 
with branches from the sympathetic, and some of them exclu- 
sively ; for this reason, it is considered a nerve of organic life. 

Fig. 131. A beautiful representation of the sympathetic ganglia and their connec- 
tion with other nerves. It is from the grand engraving of Manec, reduced in size. 
A, A, A, The semilunar ganglion and solar plexus, situated below the diaphragm 
and behind the stomach. This ganglion is situated in the region (pit of the stom- 
ach) where a blow gives severe suffering. D, D, D, The thoracic ganglia, ten or 
eleven in number. E, E, The external and internal branches of the thoracic gan- 
glia. G, H, The right and left coronary plexus, situated upon the heart. I, N, Q., 
The inferior, middle, and superior cervical ganglia. 1, The renal plexus of nerves 
that surrounds the kidneys. 2, The lumbar ganglion. 3, Their internal branches. 
4, Their external branches. 5, The aortic plexus of nerves that lies upon the aorta. 
The other letters and figures represent nervos that connect important organs and 
nerves with the sympathetic ganglia. 



What is the design of fig. 131 ? 766. How may the ganglia be consid- 
ered ? 767. What is said of the branches of the sympathetic nerve ? 



346 



ANATOMY, PHYSIOLOGY, AND HYGIENE. 



CHAPTER XXX7III. 

PHYSIOLOGY OF THE NERVOUS SYSTEM. 

768. The brain is regarded by physiologists and philoso- 
phers as the organ of the mind. Most writers consider it as 
an aggregate of parts, each charged with specific functions, 
and that these functions are the highest and most important 
in the animal economy. To the large brain, or cerebral lobes, 
they ascribe the seat of the faculties of thinking, memory, and 
the will. In man, this lobe extends so far backward as to 
cover the whole of the cerebellum. To the cerebellum, or 
little brain, is ascribed the seat of the animal, or lower pro- 
pensities. 

769. " The constant relation between mental power and 
development of brain, explains why capacities and dispositions 
are so different. In infancy, for example, the intellectual 
powers are feeble and inactive. This arises solely from the 
inaptitude of a still imperfect brain ; but in proportion as the 
latter advances toward its mature state, the mental faculties 
also become vigorous and active." 

770. We are able, in most instances, at least, to trace a 
correspondence between the development of the cerebral lobes 
and the amount of intelligence possessed by the person. The 
weight of the brain in man to that of the whole body varies 



768 — 772. Give the physiology of the nervous system. 768. How is the 
brain regarded by physiologists and philosophers ? What do they ascribe 
to the cerebrum ? To the cerebellum? 769. What does the relation be- 
tween mental powers and development of brain explain ? 770. What is 
said respecting the correspondence between the development of the brain 
and the amount of intelligence possessed by the person ? What is said of 
the weight of the brain ? 



PHYSIOLOGY OF THE NERVOUS SYSTEM. 347 

in different individuals. The heaviest brain on record was 
that of Cuvier, which weighed 4 pounds and 13 1-2 ounces. 

771. The brain likewise holds an important relation to all 
the other organs of the system. To the muscular system it 
imparts an influence which induces contraction of the fibres. 
By this relation they are brought under the control of the will. 
To ihe skin, eye, and ear, it imparts an influence that gives 
sensibility, or the power of feeling, seeing, hearing, &c. 

772. Again, the involuntary functions of the different por- 
tions of the system are more or less influenced by the brain. 
If the action of this central organ of the nervous system is 
destroyed, the functions of the digestive, respiratory, and cir- 
culatory apparatuses will be much disturbed or entirely sup- 
pressed. 

773. The brain is the seat of sensation. It perceives the 
impressions made on all parts of the body, through the medium 
of the sensitive nerves. That the impressions of external 
objects, made on these nerves, be communicated to the brain, 
where sensation is perceived, it is necessary that they be not 
diseased or injured. 

Observation. There is a plain distinction between sensa- 
tions and impressions ; the latter are the changes produced 
in the extremities of the nerve ; the former, the changes pro- 
duced in the brain and communicated to the mind. 

774. What part of the brain receives the impressions or has 
the most intimate relation with the intellectual faculties is 
unknown. Some portions, however, are of less importance 
than others. Large portions of the cortical, or outer part, are 
frequently removed without affecting the functions of this 



771. What is said of the relation of the brain to all of the organs of the 
body ? 772. Are the involuntary functions of different parts of the system 
influenced by the brain ? 773. Where is sensation perceived ? By what 
agency are the impressions of external objects conveyed to the brain ? 
What is the difference between sensations and impressions ? 774. Is it 
known what part of the brain has the most intimate relation with the intel- 
lectual faculties ? 



348 ANATOMY, PHYSIOLOGY, AND HYGIENE. 

organ. Pieces of the medullary, or central parts, have been 
removed by injuries without impairing the intellect or destroy- 
ing life. This organ, although it takes cognizance of every 
sensation, is, of itself, but slightly sensible. It may be cut, or 
parts may be removed without pain, and the individual, at 
the same time, retain his consciousness. 

775. The brain is the seat of the will. It superintends the 
physical as well as the mental movements, and the medium of 
communication from this organ to the muscles, or the parts to 
be moved, is the motor nerves. If the brain is in a quies- 
cent state, the muscles are at rest ; if, by an act of the will, 
the brain sends a portion of nervous influence to a voluntary 
muscle, it immediately contracts, and those parts to which the 
muscle is attached move. There is no perceptible interval 
between the act of the will and the motion of the part. 

776. Some physiologists assert, that the medulla oblongata 
is the point at which excitement to motion commences, and 
sensation terminates ; and also, that it possesses the power of 
originating motion in itself. 

Observation. The medulla oblongata, unlike the brain, is 
highly sensitive ; if slightly punctured, convulsions follow ; if 
much injured, respiration, or breathing, immediately ceases. 

777. It is remarkable that the nerves which arise from 
the right side of the spinal cord communicate with the left 
hemisphere of the cerebrum, and vice versa ; this results from 
the crossing of the fibres in the medulla oblongata. It follows 
from this, that if the right side of the brain receives an injury, 
the parts of the opposite side of the body lose their sensibility 
and motion. 

Observations. 1st. If the cranial nerves which are connected 



"What portions have been removed without impairing the intellect ? 
What is remarkable of the brain ? 775. What is the influence of the brain 
upon the muscles ? 776. What do some physiologists assert of the medul- 
la oblongata ? 777. What is remarkable of the nerves ? Give the 1st 
observation relative to the cranial nerves. 



PHYSIOLOGY OF THE NERVOUS SYSTEM. 349 

by a single root are divided, only the sensation of the part 
to which they are distributed is lost. Thus, if the optic nerve 
is divided, the sense of vision disappears, but the motions of 
the eye are performed as readily as before. But, if the spinal 
nerves are divided, both sensation and motion of the part to 
which they lead are destro} r ed. 

2d. When the spinal cord is divided or compressed, as in 
fractures of the spinal column, all parts below the fracture are 
paralyzed, though the nerves leading to these parts may be 
uninjured. 

3d. Again, one side of the body or one limb may become 
insensible, and the power to move it, be perfectly retained ; or 
the reverse of this may happen . — the power of motion will 
remain, while sensation is gone. In the former instance, the 
function of the posterior, or sensitive column of the spinal cord 
on one side is destroyed ; in the latter, the anterior, or motor 
column is affected. 

4th. In some cases, both sensation and motion of one side 
of the body or one limb are destroyed. In such instances, 
both the anterior and the posterior columns of one side of 
the spinal cord are diseased. 

778. Vigorous and controllable muscular contraction re- 
quires a sound and well-developed brain. If this organ is 
defective in these particulars, the movements will be ineffi- 
cient, and may be irregular. The central organ of the ner- 
vous system must, likewise, be in an active condition, to induce 
regular, steady, and controllable muscular movements. 

Observations. 1st. Persons who have suffered from apo- 
plexy and other severe diseases of the brain, have an involun- 
tary trembling of the limbs, which results from a weakened 
state of the nervous system. 

To the spinal nerves. What is said of the compression of the spinal 
cord ? Give the 3d observation relative to the spinal nerves. The 4th 
observation. 778. Upon what does vigorous controllable muscular con- 
traction depend ? What causes the involuntary trembling of the limbs 
in persons who have suffered from apoplexy ? 
30 



350 ANATOMY, PHYSIOLOGY, AND HYGIENE. 

2d. The tremor of the hand, that lessens the usefulness or 
incapacitates the fine artist or skilful mechanic, in the prime 
of life, from pursuing their vocations, may be, and is often, 
induced by the influence of intoxicating drink, which debili- 
tates and disorganizes the brain. 

3d. The tottering step, trembling hand, and shaking head 
of the aged invalid, are the results of diminished nervous 
energy, so that steady muscular contraction, so essential to 
regular movements, cannot be maintained. 

779. No difference can be discovered in the structure of 
the several kinds of nerves in any part of their course, and 
the functions they are designed to perform can only be known 
by ascertaining the place of their origin. The nerves may 
be functionally divided into five groups. 

780. 1st. Nerves of special sensation. These are the first, 
second, eighth, and it may be one of the branches of the fifth 
pair of cranial nerves. The function of these nerves is par- 
ticularly described in the chapters upon the senses of smell, 
vision, hearing, and taste. 

781. 2d. Nerves of general sensation. These embrace the 
fifth pair of cranial nerves, and the thirty-one pairs of spinal 
nerves. In those parts that require sensation for their safety 
and the performance of their functions, there is an abundant 
supply of sensitive nervous filaments. The nerves of sensa- 
tion are mostly distributed upon the skin. Few filaments 
ramify upon the mucous membranes and muscles. 

Observations. 1st. The painful sensations experienced in 
the face, and in the teeth or jaws, (tic douloureux and tooth- 
ache,) are induced by irritation and disease of a portion of 
the filaments of the fifth pair of cranial nerves. 



The tremor of the hand among some mechanics in the prime of life? 
The tottering step of the aged invalid ? 779. What is said relative to the 
structure of the nerves ? How may they be divided ? 780. Give the nerves 
of special sense. 781. Those of general sensation. Where are the nerves 
of sensation distributed ? What causes tic douloureux ? 



PHYSIOLOGY OF THE NERVOUS SYSTEM. 351 

2d. The unpleasant sensation sometimes experienced when 
we hear the grating of a file or saw, is produced by the con- 
nection of the nerve that passes across the drum of the ear 
with the fifth cranial nerve. 

3d. When pressure is made on the trunk of a nerve, the 
sensibility of the part where the nerve ramifies is modified. 
This is illustrated, when pressure is made upon the large 
nerve of the lower extremity (sciatic) in sitting upon a hard 
bench. The foot is then said to be " asleep. 1 " 

4th. When the trunk of a nerve is diseased or injured, the 
pain is experienced in the outer extremity of the nerve. A 
blow upon the elbow, which causes a peculiar sensation in the 
little finger and one side of the ring finger, affords a familiar 
illustration. This sensation is produced by injuring the ulnar 
nerve, which is distributed to the little finger. 

782. 3d. Nerves of motion. These are the third, sixth, 
and twelfth pairs of cranial nerves, and the thirty-one pairs 
of spinal nerves. These nerves are distributed to the fibres 
of the five hundred muscles of the body. The functions of 
the muscular are different from those of the sensitive nerves. 
The former are provided for the purpose of motion, and not 
of feeling. Hence, muscles may be cut, and the pain will be 
slight, compared with the cutting of the skin. This may be 
called muscular pain. Weariness is a sensation recognized 
by one set of muscular nerves. 

783. So uniformly is a separate instrument provided for 
every additional function, that there is strong reason to regard 
the muscular nerves, although running in one sheath, as in 
reality double, and performing distinct functions. Sir Charles 
Bell, in his work on the Nervous System, endeavors to show, 



How is the peculiar sensation accounted for when we hear the grating 
of a file or saw ? What produces the sensation when the foot is said to 
he " asleep ? " "What is the effect when the ulnar nerve is injured by a blow ? 
782. Give the nerves of motion. . What is said of the functions of the 
muscular nerves ? 783. What does Sir Charles Bell endeavor to show ? 



352 ANATOMY, PHYSIOLOGY, AND HYGIENE 

that one set of nervous fibres conveys the mandate from the 
brain to the muscle, and excites the contraction ; and that 
another set conveys, from the muscle to the brain, a peculiar 
sense of the state or degree of contraction of the muscle, by 
which we are enabled to judge of the amount of stimulus 
necessary to accomplish the end desired. This is obviously 
an indispensable piece of information to the mind in regu- 
lating the movements of the body. 

784. 4th. Nerves of respiration. These are the fourth, 
seventh, ninth, tenth, and eleventh pair of cranial nerves, 
also the phrenic and the external respiratory nerve. All of 
these nerves have their origin in a distinct tract or column, 
called the lateral, in the upper part of the spinal cord. Hence 
it is sometimes named the respiratory column. These nerves 
are distributed to one of the muscles of the eye ; to the mus- 
cles of the face ; to the tongue, pharynx, oesophagus, stomach, 
heart, lungs, diaphragm, and some of the muscles of the neck 
and chest. 

785. It is through the instrumentality of the accessory, 
phrenic, and external respiratory nerves, (10, 11, 12, 13, fig. 
132,) that the muscles employed in respiration are brought 



Fig. 132. The distribution of the respiratory nerves, a, Section of the brain and 
medulla oblongata, b, The lateral columns of the spinal cord, c, c, The respiratory 
tract of the spinal cord, rf, The tongue, c, The larynx. /, The bronchia, g, The 
oesophagus. A, The stomach, i, The diaphragm. 1, The pneumogaslric nerve. 
2, The superior laryngeal nerve. 3, The recurrent laryngeal nerve. (These two 
ramify on the larynx.) 4, The pulmonary plexus of the tenth nerve. 5, The cardiac 
plexus of the tenth nerve. These two plexuses supply the heart and lungs with ner- 
vous filaments. 7, The origin of the fourth pair of nerves, that passes to the superior 
oblique muscle of the eye. 8, The origin of the facial nerve, that is spread out on the 
side of the face and nose. 9, The origin of the glossopharyngeal nerve, that passes 
to the tongue and pharynx. 10, The origin of the spinal accessory nerve. 11, This 
nerve penetrating the sterno-mastoideus muscle. 12, The origin of the internal res- 
piratory or phrenic nerve, that is seen to ramify on the diaphragm. 13, The origin of 
the external respiratory nerve, that ramifies on the pectoral and scaleni muscles. 

784. Give the respirator}'' nerves. "What is said in reference to the respira- 
tory nerves ? 785. Through the agency of what nerves are the respiratory 
muscles brought into action ? Explain fig. 132. 



PHYSIOLOGY OF THE NERVOUS SYSTEM. 353 

Fig. 132. 




354 ANATOMY, PHYSIOLOGY, AND HYGIENE. 

into action without the necessity of the interference of the 
mind. Though to a certain extent they may be under the 
influence of the will, yet it is only in a secondary degree. No 
one can long suspend the movements of respiration ; * for in 
a short time, instinctive feeling issues its irresistible mandate, 
which neither requires the aid of erring wisdom, nor brooks 
the capricious interference of the will. 

786. The fourth, seventh, and tenth pairs of nerves, (7, 8, 
9, fig. 132,) with the spinal accessory, phrenic, and external 
respiratory, are not only connected with the function of respi- 
ration, but contribute to the expression of the passions and 
emotions of the mind. 

787. The influence of this order of nerves in the expres- 
sion of the passions, is strikingly depicted in Sir Charles Bell's 
Treatise on the Nervous System. " In terror," he remarks, 
" we can readily conceive why a man stands with his eyes 
intently fixed on the object of his fears — the eyebrows ele- 
vated, and the eyeballs largely uncovered ; or why, with 
hesitating and bewildered steps, his eyes are rapidly and 
wildly in search of something. In this way, we only perceive 
the intense application of his mind to the objects of his appre- 
hension, and its direct influence on the outward organs." 

788. " But when we observe him further, there is a spasm 
in his breast ; he cannot breathe freely ; the chest remains 
elevated, and his respiration is short and rapid. There is a 



* Dr. EHiotson, and some other writers on physiology, have detailed 
cases of death from voluntary suspension of respiration. But these 
cases are not conclusive, as examinations were not made, so as to 
determine positively, that death did not result from disease of the 
heart, brain, or some other vital organ. 

Can respiration be suspended for any considerable length of time ? 
786. "What nerves contribute to the expression of the passions and emo- 
tions of the mind ? 787, 788. What does Sir Charles Bell say of the influ- 
ence of this order of nerves in the expression of the passions ? 



PHYSIOLOGY OF THE NERVOUS SYSTEM. 355 

gasping and convulsive motion of his lips, a tremor on his 
hollow cheeks, a gasping and catching of his throat ; his 
heart knocks at his ribs, while yet there is no force in -the 
circulation — the lips and cheeks being ashy pale." 

789. " These nerves are the instruments of expression, 
from the smile upon the infant's cheek, to the last agony of 
life. It is when the strong man is subdued by this mysterious 
influence of soul on body, and when the passions may be 
truly said to tear the heart, that we have the most afflicting 
picture of human frailty, and the most unequivocal proof 
that it is the order of functions we have been considering, 
that is thus affected. In the first struggle of the infant to 
draw breath, in the man recovering from a state of suffoca- 
tion, and in the agony of passion, when the breast labors from 
the influence at the heart, the same system of parts is affected, 
the same nerves, the same muscles, and the symptoms or 
character have a strict resemblance." 

790. The seventh pair of nerves not only communicates 
the purposes of the will to the muscles of the face, but at the 
same time it calls them into action, under the influence of 
instinct and sympathy. On this subject a late writer remarks, 
" How expressive is the face of man ! How clearly it an- 
nounces the thoughts and sentiments of the mind ! How well 
depicted are the passions on his countenance ! tumultuous 
rage, abject fear, devoted love, envy, hatred, grief, and every 
other emotion, in all their shades and diversities, are imprinted 
there, in characters so clear that he that runs may read ! 
How difficult, nay, how impossible, is it to hide or falsify 
the expressions which indicate the internal feelings ! Thus 
conscious guilt shrinks from detection, innocence declares its 
confidence, and hope anticipates with bright expectation." 

Observation. The fifth pair of nerves (fig. 126) is dis- 

789. Are they also the instruments of expression, either of joy or grief? 
790. "What is said in reference to the seventh pair of nerves ? Where is 
the fifth pair of nerves distributed ? 



356 ANATOMY, PHYSIOLOGY, AND HYGIENE. 

tributed to the parts of the face on which the seventh pair 
ramifies. The former serves for sensation, the latter for 
motion. Thus, when the seventh pair of nerves is divided, 
or its functions destroyed by disease, the side affected loses 
all power of expression, though sensation remains unaffected. 
On the contrary, if we divide the fifth pair, sensation is 
entirely destroyed, while expression remains. 

791. 5th. The sympathetic nerve. This nerve confers vitality 
on all the important portions of the system. It exerts a con- 
trolling influence over the involuntary functions of digestion, 
absorption, secretion, circulation, and nutrition. Every por- 
tion of the body is, to a certain extent, under its influence, as 
filaments from this system of nerves accompany the blood- 
vessels throughout their course. 

792. An important use of the sympathetic nerve is to 
form a communication of one part of the system with another, 
so that one organ can take cognizance of the condition of 
every other, and act accordingly. If, for example, disease 
seizes the brain, the stomach, by its sympathetic connection, 
knows it ; and as nourishment would add to the disease, it 
refuses to receive food, and perhaps throws off what has 
already been taken. Loss of appetite in sickness is thus a 
kind provision of nature, to prevent our taking food when it 
would be injurious ; and following this intimation, we, as a 
general rule, should abstain from food until the appetite returns. 

Fig. 133. A back view of the brain and spinal cord. 1, The cerebrum. 2, The 
cerebellum. 3, The spinal cord. 4, Nerves of the face. 5, The brachial plexus of 
nerves. 6, 7,8, 9, Nerves of the arm. 10, Nerves that pass under the ribs. 11, The 
lumbar plexus of nerves. 12, The sacral plexus of nerves. 13, 14, 15, 16, Nerves of 
the lower limbs. 

"What is the function of this nerve ? What is the effect if the seventh 
pair is divided, or its function destroyed by disease ? 791. What is said of 
the sympathetic nerve ? 792. What is the use of the sympathetic system ? 
Explain fig. 133. 

Note. Let the anatomy and physiology of the nervous system be 
reviewed from figs. 131, 132, 133, or from anatomical outline plate, No. 8. 



PHYSIOLOGY OF THE NERVOUS SYSTEM. 
Fig. 133. 



357 




358 ANATOMY, PHYSIOLOGY, AND HYGIENE. 



CHAPTER XXXIX. 

HYGIENE OF THE NERVOUS SYSTEM. 

793. As the different organs of the system are dependent 
on the brain and spinal cord for efficient functional action, 
and as the mind and brain are closely associated during 
life, the former acting in strict obedience to the laws which 
regulate the latter, it becomes an object of primary impor- 
tance in education, to discover what these laws are, that 
we may escape the numerous evils consequent on their 
violation. 

794. For healthy and efficient action, the brain should be 
primarily sound ; as this organ is subject to the same gen- 
eral laws as other parts of the body. If the brain of the 
child is free from defects at birth, and acquires no improper 
impressions in infancy, it will not easily become diseased in 
after life. But, if the brain has inherited defects, or has ac- 
quired a proneness to disease by mismanagement in early life, 
it will more easily yield to influences that cause diseased 
action. The hereditary tendency to disease is one of the 
most powerful causes that produce nervous and mental affec- 
tions. Consequently, children have a strong tendency to the 
diseases from which the parents suffered. 

795. When both parents have similar defects, or have 
descended from tainted families, the children are usually more 
deeply impressed with their imperfections than when only one 

793 — 850. Give the hygiene of the nervous system. 793. Why is it im- 
portant to know the laws which regulate the action of the brain ? 

794. What is necessary that the action of the brain be healthy and effi- 
cient ? What follows if the brain of the child has inherited defects ? 

795. What is the effect when both parents possess similar defects ? 



HYGIENE OF THE NERVOUS SYSTEM. 359 

possesses the defect. This is the reason of the frequency of 
nervous disease and imbecility among the opulent, as inter- 
marriages among near relations are more frequent with this 
class than among the poor. 

Observation. Among some of the reigning families of 
Europe, particularly the Spanish, the folly of intermarriage 
among themselves is strongly illustrated. The high and noble 
talents that characterized their progenitors are not seen, but 
there is now exhibited, among their descendants, imbecility 
and the most revolting forms of nervous disease. 

796. " Unhappily, it is not merely as a cause of disease, that 
hereditary predisposition is to be dreaded. The obstacles 
which it throws in the way of permanent recovery are even 
more formidable, and can never be entirely removed. 
Safety is to be found only in avoiding the perpetuation 
of the mischief." 

797. " Therefore, if two persons, each naturally of excitable 
and delicate nervous temperament, choose to unite for life, 
they have themselves to blame for the concentrated influence 
of similar tendencies in destroying the health of their off- 
spring, and subjecting them to all the miseries of nervous 
disease, madness, or melancholy." The command of God 
not to marry within certain degrees of consanguinity, is in 
accordance with the organic laws of the brain, and the 
wisdom of the prohibition is confirmed by observation. 

Observation. The inhabitants, females particularly, of the 
sea-girt islands of America, are more affected with nervous 
diseases, than those who reside upon the mainland. The 
prevalence of these affections is ascribed to the. frequent 
intermarriage of persons closely related by blood. . 



"What is one cause of nervous disease among the higher classes ? "What 
is true of some of the reigning families of Europe ? 796. Why is heredi- 
tary predisposition to be dreaded ? 797- Is the prohibition of God respect- 
ing intermarriage in accordance with the organic laws of the brain r 
"What is said of the inhabitants of the sea-girt islands of America ? 



360 ANATOMY, PHYSIOLOGY, AND HYGIENE. 

798. The brain requires a due supply of pure blood. This 
organ receives an unusually large supply of blood, in com- 
parison with the rest of the body. It is estimated that one 
tenth of all the blood sent from the heart goes to this organ. 
If the arterial blood be altogether withdrawn, or a person 
breathes air that is filled with carboni} gas, the brain ceases 
its proper action, and sensibility with consciousness becomes 
extinct. 

Illustrations. 1st. If a person lose a considerable quantity 
of blood, dizziness and loss of consciousness follow. This 
results from the brain not receiving a sufficient amount of 
blood to sustain its functions. 

2d. When an individual descends into a well or pit that con- 
tains carbonic acid, the blood is not changed or purified in 
the lungs, and loss of consciousness and death soon follow. 

799. The slighter variations in the state of the blood have 
equally sure, though less palpable effects- If its vitality is 
impaired by breathing an atmosphere so much vitiated as to 
be insufficient to produce the proper degree of oxygenation, 
the blood then affords an imperfect stimulus to the brain. As 
a necessary consequence, languor and inactivity of the men- 
tal and nervous functions ensue, and a tendency to headache, 
fainting, or hysteria, makes its appearance. 

Observations. 1st. Let a person remain, for a time, in a 
crowded, ill-ventilated, hall or church, and headache or faint- 
ness is generally produced. This is caused by the action of 
impure blood upon the brain. 

2d. If a school-teacher wishes to have his pupils, on the 
day of examination, appear creditably, he will be careful to 
have the room well ventilated. Ventilating churches might 

798. Why does the brain require a due supply of pure blood ? What is the 
effect when a person loses a considerable quantity of blood ? What causes 
the loss of consciousness when carbonic acid is breathed ? 799. What 
effects are produced by slight variations in the quality of the blood ? From 
the following observations, give some of the effects of impure blood on 
the brain. 



HYGIENE OF THE NERVOUS SYSTEM. 361 

prevent the inattention and sleepiness that are observed 
during the afternoon service. 

3d. In many instances, the transmission of imperfectly 
oxygenated blood to the brain, is an influential cause in the 
production of nervous disease and delicacy of constitution. 
The only efficient remedy for these conditions is a supply of 
pure blood to the brain. 

800. The brain should be called into action. This organ, 
like the muscles, should be used, and then allowed to rest, or 
cease from vigorous thought. When the brain is properly 
called into action by moderate study, it increases in size and 
strength ; while, on the other hand, if it is not used, the 
action of this organ is enfeebled, thereby diminishing the 
function of all parts of the body. 

801. The brain, being an organized part, is subject, so far 
as regards exercise, to the same laws as the other organs of 
the body. If it is doomed to inactivity, its size diminishes, its 
health decays, and the mental operations and feelings, as a 
necessary consequence, become dull, feeble, and slow. If it 
is duly exercised after regular intervals of repose, the mind 
acquires readiness and strength. Lastly, if it is overtasked, 
either in the force or duration of its activity, its functions 
become impaired, and irritability and disease take the place of 
health and vigor. 

802. The consequences of inadequate exercise will first be 
explained. We have seen that by disuse the muscles become 
emaciated, the bones soften, and the blood-vessels are oblit- 
erated. The brain is no exception to this general rule. It is 
impaired by permanent inactivity, and becomes less fit to 
manifest the mental powers with readiness and energy. Nor 
will this surprise any reflecting person, who considers that the 

800. Why should the brain be called into action ? 801. What is the 
effect if the brain is doomed to inactivity ? 802. Show the consequences of 
disuse of the organs mentioned in preceding chapters. Does the same 
principle apply to the brain ? 

31 



362 ANATOMY, PHYSIOLOGY, AND HYGIENE. 

brain, as a part of the same animal system, is nourished by 
the same blood and regulated by the same vital laws as the 
muscles, bones, and arteries. 

803. It is the weakening and depressing effect which is 
induced by the absence of the stimulus necessary for the 
healthy exercise of the brain, that renders solitary confine- 
ment so severe a punishment, even to the most daring minds. 
Keeping the above principle in view, we shall not be surprised 
to find that non-exercise of the brain and nervous system, or, 
in other words, inactivity of intellect and feeling, is a very 
frequent predisposing cause of every form of nervous disease. 

804. For demonstrative evidence of this position, we have 
only to look at the numerous victims to be found among 
females of the middle and higher ranks, who have no calls to 
exertion in gaining the means of subsistence, and no objects 
of interest on which to exercise their mental faculties, and 
who, consequently, sink into a state of mental sloth and 
nervousness, which not only deprives them of much enjoy- 
ment, but subjects them to suffering, both of body and mind, 
from the slightest causes. 

805. But let the situation of such persons be changed: 
bring them, for instance, from the listlessness of retirement 
to the business and bustle of the city ; give them a variety of 
imperative employments, and so place them in society as to 
supply to their cerebral organs that extent of exercise which 
gives health and vivacity of action, and in a few months the 
change produced will be surprising. Health, animation, and 
energy, will take the place of former insipidity and dulness. 

806. An additional illustration, involving an important prin- 
ciple in the production of many distressing forms of disease 

803. What renders solitary confinement so severe a punishment to the 
most daring minds ? What is a predisposing cause of nervous disease ? 
804. In what classes do mental and nervous debility prevail ? 805. Hoav 
can this be counteracted ? 836. Give another illustration, showing how 
disease of the brain is. induced. 



HYGIENE OF THE NERVOUS SYSTEM. 363 

will be found in the case of a man of mature age, and of 
active habits, who has devoted his life to the toils of business, 
and whose hours of leisure have been few and short. Sup- 
pose such a person to retire to the country in search of repose, 
and to have no moral, religious, or philosophical pursuits to 
occupy his attention and keep up the active exercise of his 
brain ; this organ will lose its health, and the inevitable result 
will be, weariness of life, despondency, or some other variety 
of nervous disease. 

807. One great evil attending the absence of some imper- 
ative employment or object of interest, to exercise the mind 
and brain, is the tendency which it generates to waste the 
mental energies on every trifling occurrence which presents 
itself, and to seek relief in the momentary excitement of any 
sensation, however unworthy. The best remedy for these 
evils is to create occupation to interest the mind, and give 
that wholesome exercise to the brain, which its constitution 
requires. 

808. The evils arising from excessive or ill-timed exercise 
of the orain, or any of its parts, are numerous. When we 
use the eye too long, or in too bright a light, it becomes blood- 
shot. The increased action of its vessels and nerves gives 
rise to a sensation of fatigue and pain, requiring us to desist. 
If we relieve the eye, the irritation gradually subsides and 
the healthy state returns. But, if we continue to look intently, 
or resume our employment before the eye has regained its 
natural state by repose, the irritation at last becomes perma- 
nent, and disease, followed by weakness of vision, or even 
blindness, may ensue. 

809. Phenomena precisely analogous occur, when, from 

837. What is one great evil attending the absence of some imperative 
employment to exercise the mind and brain ? "What is the true remedy for 
these evils ? 808. From what other cause do evils arise to the brain ? 
Explain the evil of it by the excessive use of the eye. 809. What is the 
only difference in the analogy of the phenomena of the eye and brain ? Has 
the analogy been verified ? 



364 ANATOMY, PHYSIOLOGY, AND HYGIENE. 

intense mental excitement, the brain is kept long in a state of 
excessive activity. The only difference is, that we can always 
see what happens in the eye, but rarely what takes place in 
the brain ; occasionally, however, cases of fracture of the skull 
occur, in which, part of the bone being removed, we can see 
the quickened circulation in the vessels of the brain, as easily 
as those of the eye. 

810. Sir Astley Cooper had a young man brought to him, 
who had lost a portion of his skull, just above the eyebrow. 
" On examining the head," says Sir Astley, " I distinctly saw 
that the pulsation of the brain was regular and slow ; but at 
this time he was agitated by some opposition to his wishes, 
and directly the blood was sent with increased force to the 
brain, and the pulsation became frequent and violent." 

811. Indeed, in many instances, the increased circulation 
in the brain, attendant on mental excitement, reveals itself 
when least expected, and leaves traces after death, which are 
very perceptible. When tasked beyond its strength, the eye 
becomes insensible to light, and no longer conveys any im- 
pressions to the mind. In like manner, the brain, when much 
exhausted, becomes incapable of thought, and consciousness 
is almost lost in a feeling of utter confusion. 

812. At any time of life, excessive and continued mental 
exertion is hurtful ; but in infancy and early youth, when the 
structure of the brain is still immature and delicate, perma- 
nent mischief is more easily produced by injudicious treat- 
ment than at any subsequent period. In this respect, the 
analogy is as complete between the brain and the other parts 
of "-the bod^y, as that exemplified in the injurious effects of pre- 
mature exercise of the bones and muscles. 

813. Scrofulous and rickety children are the most usual 

810. Relate the case detailed by Sir Astley Cooper. 81 L. May the 
increased functional action of the brain change its structure ? 812. At 
what age particularly is excessive and continued mental exertion hurtful ? 
813. "What is said of scrofulous and rickety children ? 



HYGIENE OF THE NERVOUS SYSTEM. 365 

sufferers in this way. They are generally remarkable for 
large heads, great precocity of understanding, and small, deli- 
cate bodies. But in such instances, the great size of the brain, 
and the acuteness of the mind, are the results of morbid 
growth. Even with the best of management, the child passes 
the first years of its life constantly on the brink of active 
disease. 

814. Instead, however, of trying to repress its mental 
activity, the fond parents, misled by the early promise of 
genius, too often excite it still further, by unceasing cultiva- 
tion, and the never-failing stimulus of praise. Finding its 
progress for a time equal to their warmest wishes, they look 
forward with ecstasy to the day when its talents will break 
forth and shed lustre on its name. 

815. But in exact proportion as the picture becomes 
brighter to their fancy, the probability of its being realized 
becomes less; for the brain, worn out by premature exertion, 
either becomes diseased, or loses its tone, leaving the mental 
powers imbecile and depressed for the remainder of life. The 
expected prodigy is thus easily outstripped in the social race 
by many whose dull outset promised him an easy victory. 

816. Taking for our guide the necessities of the constitu- 
tion, it will be obvious that the modes of treatment commonly 
resorted to ought to be reversed. Instead of straining to the 
utmost the already irritable powers of the precocious child, 
and leaving his dull competitor to ripen at leisure, a systematic 
attempt ought to be made, from early infancy, to rouse to action 
the languid faculties of the latter, while no pains ought to be 
spared to moderate and give tone to the activity of the former. 

817. Instead of this, however, the prematurely intelligent 
child is sent to school and tasked with lessons at an unusually 

814. How are such children usually managed ? 815. "What is the cause 
of their early promise and subsequent disappointment ? 816. What mode 
of treatment should be adopted in educating precocious children ? 
817- How should the dull or less active child be treated ? What is the 
usual course ? 

31* 



366 ANATOMY, PHYSIOLOGY, AND HYGIENE. 

early age, while the healthy but more backward boy, who 
requires to be stimulated, is kept at home in idleness, per- 
haps for two or three years longer, merely on account of 
his backwardness. A double error is here committed. The 
consequences to the intelligent boy are, frequently, the per- 
manent loss both of health and of his envied superiority of 
intellect. 

818. In youth, too, much mischief is done by the long 
daily period of attendance at school, and the continued appli- 
cation of the mind which the ordinary system of education 
requires. The law of exercise — that long-sustained action 
exhausts the vital powers of the organ — applies as well to 
the brain as to the muscles. Hence the necessity of varying 
the occupations of the young, and allowing frequent intervals 
of exercise in the open air, instead of " enforcing the continued 
confinement now so common." 

Observation. It is no unusual occurrence, that on examina- 
tion day, the best scholars appear indifferently. This may be 
the resetlt of nervous exhaustion, produced by extra mental 
effort in preparing for the final examination. It is advisable 
for such pupils to divert their minds from close study for a 
few days previous to examination. During this time, the 
student may indulge in physical recreation, social intercourse, 
and a moderate amount of reading. 

819. " In early and middle life, fever, an unusual degree 
of cerebral disorder, is a common consequence of the exces- 
sive and continued excitement of the brain. This unhappy 
result is brought on by severe study, unremitted mental exer- 
tion, anxiety, and watching. Nervous disease, from excessive 
mental labor and high mental excitement, sometimes shows 
itself in another form. 



What are the consequences of the error ? 818. What error prevails in the 
present system of education ? Why should youths be allowed frequent 
intervals to exercise in the open air ? Give observation. 819. What is a 
frequent consequence of continued and excessive excitement of the brain ? 



HYGIENE OF THE NERVOUS SYSTEM. 367 

820. " From the want of proper intervals of rest, the vascu- 
lar excitement of the brain has not time to subside. A restless 
irritability of temper and disposition comes on, attended with 
sleeplessness and anxiety, for which no external cause can be 
assigned. The symptoms gradually become aggravated, the 
digestive functions give way, nutrition is impaired, and a 
sense of wretchedness is constantly present, which often leads 
to attempts at suicide." 

Observations. 1st. Moderation in mental exertion is more 
necessary in old age than in early or mature years. In youth 
and manhood, the exhaustion of the brain from over-excite- 
ment may be repaired, but no such result follows over-exer- 
tion in the decline of life. " What is lost then, is lost forever." 
At that period, the brain becomes excited, and is soon exhausted 
when forced to protracted and vigorous thought. Sir Waiter 
Scott and President Harrison afford sad examples of prema- 
ture death from overtasked brains at an advanced period of 
.their lives. 

2d. If the mind is incessantly engaged in the contemplation 
of the same object, there is danger from over-exertion of the 
brain at any period of life, but more particularly in old age. 
The more limited the sphere of mental action, the greater the 
danger of the brain • being over-exercised. Hence the fre- 
quency of nervous diseases in poets, mathematicians, and 
musicians. 



820. "What often manifests itself from the want of proper intervals of 
rest ? "Why is moderation in mental action necessary in old age ? "What 
is the effect if the mind is incessantly engaged in the contemplation of the 
same object ? 



ANATOMY, PHYSIOLOGY, AND HYGIENE. 



CHAPTER XL. 

HYGIENE OE THE NERVOUS SYSTEM, CONTINUED. 

821. Having pointed out the evils arising both from inade- 
quate and from excessive mental exertion, it remains to direct 
the attention to some of the rules which should guide us in 
the exercise of the brain. 

822. We should not enter upon continued mental exertion, 
or arouse deep feeling, immediately before or after a full 
meal. Such is the connection between the mind and body, 
that even in a perfectly healthy person, unwelcome news, 
sudden anxiety, or mental excitement, occurring soon after 
eating, will impede digestion, and cause the stomach to loathe 
the masticated food. 

823. The worst forms of indigestion and nervous depres- 
sion are those which arise from excessive mental application, 
or depressed feeling, conjoined with unrestrained indulgence in 
the pleasures of the table. In such circumstances, the stom- 
ach and brain react upon and disturb each other, till all the 
horrors of nervous disease make their unwelcome appearance, 
and render life miserable. Too many literary men and 
students know this from sad experience. 

824. We should engage in intense study in the early part 
of the day. Nature has allotted the darkness of the night for 
repose, and for restoration by sleep of the exhausted energies 
of mind and body. In the early part of the evening, if stud}? - 
or composition be ardently engaged in, the increased action 

822. Why should we not arouse deep feeling immediately before or after 
eating a full meal ? 823. How are the worst forms of indigestion and ner- 
vous depression produced ? "What class of men know this from sad experi- 
ence ? 824. What evils arise from studious application at night ? 



HYGIENE OF THE NERVOUS SYSTEM. 369 

of the brain, which always accompanies activity of mind, 
requires a long time to subside. If the individual possesses a 
nervous temperament, he will be sleepless for hours after he 
has retired, or perhaps be tormented by unpleasant dreams. 

825. It is, therefore, of great advantage to enter upon 
intense mental application early in the day, and to devote 
several of the hours which precede bedtime to entertaining 
conversation, music, and lighter reading. The vascular excite- 
ment previously induced in the brain by study, has then time 
to subside, and sound, refreshing sleep is much more cer- 
tainly obtained. This rule is of great consequence to those 
who are obliged to undergo much mental labor. 

Observation. The idea of gathering wisdom by burning 
the "midnight oil," is more poetical than profitable. The 
best time to use the brain is during the day. 

826. The close student and the growing child need more sleep 
than the idler or the adult. As sleep is the natural repose of 
all organs, it follows that the more the brain and other organs 
of the system are employed, the more repose they require. 
The organs of the child, beside sustaining their proper func- 
tions, are busy in promoting its growth. This nutritive process 
is attended with a certain degree of exhaustion. The impaired 
health of children often results from a disregard of this prin- 
ciple. But, on the other hand, an excess of sleep produces 
feebleness, by preventing the proper exercise of the mind as 
well as the body. 

827. The length of time the brain may be advantageously 
used, is modified by many circumstances. The power of the 
brain in different persons to endure action, is various. This 
is modified by its primary character ; by development and 
age ; by habits of action ; by the health of the cerebral organ 

825. Why should we engage in intense study in the early part of the day ? 
826. What persons require the most sleep ? Why ? 827. What is said 
relative to the length of time that the brain can be advantageously used ? 
Give a condition that modifies the amount of mental labor. 



370 ANATOMY, PHYSIOLOGY, AND HYGIENE. 

and general system ; by the moral feelings and other con- 
ditions. 

828. The primary physical organization of some indi- 
viduals is such, that they are enabled to endure with impunity 
an amount of mental labor that would disorder, if not de- 
stroy functionally, the cerebral organ of others differently 
constituted. Napoleon Bonaparte was of this number. There 
can be no fixed period for mental labor, that may be adopted 
as a rule for all persons whose systems are maturely developed. 
Much less is there a proper definite period for study, that is 
applicable to all children. 

Observation. The practice of retaining pupils of all ages, 
from five to twenty years, in the school-room the same period of 
time, for the purpose of study, is not predicated upon any law 
of physiology. An exercise of three hours, with one or two 
recesses of ten minutes each, may profit the eldest class ; two 
hours with a recess of ten minutes, the middle class ; while 
one hour, or one hour and a half, with one recess, would be as 
long a period as the youngest pupils should be retained in the 
study-room at one session. 

829. A person who is accustomed to muscular exertion 
will endure a longer period of physical toil than one who is 
not inured to it. So it is with mental labor. If the brain has 
been habituated to mental action and profound study, it will 
not be so soon fatigued as when not accustomed to such 
exertions ; consequently, an amount of mental labor may be 
performed with impunity at one time, that would exhaust and 
cause serious disease of the cerebral organ at another. 

Observation. Persons that commence a course of study 
at a late period in life, frequently evince their zeal at the 



828. "Why can there be no fixed period for mental labor ? What is said 
of the practice of retaining pupils of all ages the same period of time in 
the school-room ? 829. Show that the action of the brain is influenced by- 
habit, as well as the muscular system. What suggestion to those persons 
that commence a course of study at a late period in life ? 



HYGIENE OF THE NERVOUS SYSTEM. 371 

commencement by poring over their books twelve or more 
hours each day. The progress of such students is soon 
arrested by physical and mental depression. In such instances, 
it would be more judicious to commence with only three or 
four hours' vigorous application each day, and gradually pro- 
tract the period of study five or more minutes eveiy succes- 
sive day, until the brain may be called into vigorous action six 
or eight hours with impunity. 

830. The amount of mental power is greatly influenced 
by the general health. Such is the intimate connection of the 
difTerent parts of the system, particularly the digestive appara- 
tus, with the cerebral organs, that except there be vigor of 
constitution, and freedom from disease, mental efforts will be 
feeble and of little avail. 

Observation. The prevalent opinion, that individuals who 
are feeble or diseased may acquire a collegiate education, and 
thus become useful to themselves and the community, is very 
generally erroneous. Such persons should enter upon a daily 
and systematic course of physical training, and their labor 
should be in the open air, in order that the system may be 
invigorated and freed from disease. 

831. The moral feelings exert a controlling influence over 
the functions of the muscular, digestive, and respiratory 
organs. They also exert an influence, perhaps, more pow- 
erful upon the nervous system. While fear and anxiety 
depress, hope and the enlivening emotions, facilitate the func- 
tional activity of the brain, and increase its power for mental 
exertion. By a proper and systematic education of the 
moral feelings, they are not only a source of happiness, and 
productive of right conduct, but aid in the culture of the 



830. Show that the amount of mental power is modified by the general 
health. What is said of feeble persons acquiring a collegiate education ? 
831. Do the moral feelings exert a controlling influence over the principal 
functions of the system ? What is the effect of a proper and systematic 
culture of the moral feelings ? 



372 ANATOMY, PHYSIOLOGY, AND HYGIENE. 

intellect. Consequently, we should cultivate a feeling of hope- 
ful trust in the future, and a firm reliance upon the laws which 
the Creator has given us for our guidance. 

832. Regularity is very important in exercising the moral 
and intellectual powers. Periodicity, or a tendency to resume 
the same mode of action at stated times, is peculiarly the 
characteristic of the nervous system. If we repeat any kind 
of mental effort every day at the same hour, we at last find 
ourselves entering upon it without premeditation when the 
time approaches. In like manner, if we arrange our studies 
in accordance with this law, and take up each" in the same 
order, a natural aptitude is soon produced, which renders 
application more easy than by resuming the subjects as acci- 
dent may direct. 

Observation. When engaged in abstruse studies, it may be 
found advantageous to pursue others that are less difficult. 
The intense application of the brain, which is requisite in the 
one instance, is relieved by directing the attention to a study 
that requires less thought. By this change, there is mental 
relaxation attended with invigoration of the cerebral organ. 
Or, it may be explained by assuming, that the brain is com- 
posed of an aggregate of distinct organs, each of which is 
called into action in pursuing different studies. 

833. Effective study is impossible if the powers of the 
brain are depressed. When the cerebral organ has been 
temporarily debilitated by protracted intellectual efforts, it is 
ineffectual to attempt any concentrated mental exercise. This 
condition of the nervous system is indicated by confusion of 
thought and inability to attain results that usually follow simi- 
lar efforts. Mental rest in these cases is required. 

Observation. Students frequently fail in solving mathe- 

832. Why is regularity of great importance in exercising the moral and 
intellectual powers ? What suggestion when pursuing abstruse studies ? 
How explained ? 833. When is effective study impossible ? How is this 
condition of the nervous system indicated ? 



HYGIENE OF THE NERVOUS SYSTEM. 373 

matical problems when the mind is prostrated by continued 
and excessive effort to obtain a solution. Not unfrequently 
after a night's rest the problem is quickly solved, and the 
pupil thinks he " dreamed it out." The true explanation is, 
rest invigorated the exhausted brain, which fitted it for vigor- 
ous and successful thought. 

834. The intellect should not be cultivated to the neglect 
of the moral and physical powers. All the faculties require 
for their development regular exercise, alternated with inter- 
vals of rest. This is as necessary to the due development 
of the moral feelings of a child as in physical training and 
mental culture. Consequently, those schools are to be pre- 
ferred in the education of youth, where the physical, intellec- 
tual, and moral faculties receive each day a due share of 
attention and culture. 

835. The continuance of healthy and vigorous action in 
the matured physical, mental, and moral powers, requires 
frequent and regular action, alternated with rest, as much as 
in their development. Consequently, those who cultivate one 
or two of these faculties, to the neglect of the others, exhibit 
a marked deficiency of acuteness and vigor in those not 
exercised. This defect reacts on the powers that are vigor- 
ous, diminishing the energy and deteriorating all the other 
faculties of man. 

Observations. 1st. If the principles before mentioned are 
true, the adult, as well as the child, should spend a part of 
each day in some proper physical employment ; another por- 
tion should be appropriated to intellectual pursuits ; while 
another should be sedulously devoted to the cultivation of 
the moral feelings. 

2d. Disease of the corporeal system more frequently occurs 

How is the "dreaming out" of problems explained? 834. "What is said 
of the culture of the intellect ? What schools are preferable in the edu- 
cation of youth ? Why ? 835. What is the effect of cultivating only one 
faculty of the mind ? Give observation 1st. Observation 2d. 
32 



376 ANATOMY, PHYSIOLOGY, AND HYGIENE. 

al a later period. The fatigue is thus doubled, and the suc- 
cess greatly diminished. 

841. "The best way is to begin at the proper age, and to 
persevere till the end is attained. This accustoms the mind 
to sound exertion, and not to fits of attention. Hence the 
evil arising from long vacations ; and also the evil of beginning 
studies before the age at which they can be understood, as in 
teaching children the abstract rules of grammar, to succeed 
in which, implies in them a power of thinking, and an amount 
of general knowledge, which they do not possess." 

842. The skull is susceptible of fractures from slight 
blows. This occurs most frequently when the blow is given 
on the side of the head above and anterior to the ear. 
Here the bone is very thin, and often quite brittle. For these 
reasons, no instructor, or any person, should punish a child by 
striking upon any portion of the head. 

Observation. A few years since, a teacher in one of the 
Middle States gave a pupil a slight blow upon the head. It 
fractured the skull and ruptured a blood-vessel of the brain, 
causing a loss of consciousness, and finally death. 

843. Concussion of the brain may be produced by blows, or 
by violently shaking a person. As the brain is of pulpy con- 
sistence, the atoms of which it is composed, and the circula- 
tion of blood in its minute vessels, may be disturbed by the 
vibration from a blow on the exterior of the skull-bones. This 
disturbance of the cerebral organ is attended with unpleasant 
sensations, dizziness, loss of memory and consciousness. 
These may be followed by headache and inflammation of the 
brain. Concussion of the brain, and the results above men- 
tioned, may be produced by the sudden motion attendant on 
the violent shaking of a scholar. Consequently, a child should 

841. What is the best way of learning the sciences ? 842. "Why should 
not a child be struck upon any portion of the head ? What observation 
in this connection ? 843. How may concussion of the brain be produced ? 
What is the effect of each upon the brain of the child ? 



HYGIENE OF THE NERVOUS SYSTEM. 377 

never be seized by the arm and shaken violently as a method 
of chastisement. 

Observation. Most persons have experienced a disagree- 
able sensation and dizziness, caused by falling from a slight 
elevation, or by jumping from a carriage. This is the result 
of a moderate concussion of the brain. 

844. In injuries of the brain, from blows and falls, the 
symptoms are usually alarming, and all should possess some 
information for such contingencies. In general, such acci- 
dents are attended by insensibility ; the skin and extremities 
are pale and cold, the pulse is very weak and feeble, and the 
circulation is less vigorous ; the respiration, also, is less fre- 
quent and full. 

845. When these symptoms exist, the individual, in the 
first instance, should be placed in pure air, and friction and 
dry warmth should be applied to the pallid and cold skin. 
This should be assiduously persevered in until heat and color 
are restored to the skin and limbs, and due action of the heart 
and arteries has been established. Mild stimulants may also 
be used internally, with much advantage. The sympathizing 
friends should not be permitted to stand about the patient, as 
they vitiate the air. There should be no bleeding until the 
skin and extremities become warm. Send for a surgeon with- 
out delay. 

Give an instance where moderate concussion of the brain is produced. 
844. What are the symptoms when the brain is injured from blows and 
falls ? 845. "What treatment should be adopted ? 

32* 



378 ANATOMY, PHYSIOLOGY, AND HYGIENE. 

CHAPTER XLI. 

THE SENSE OF TOUCH. 

846. Sensation is the perception of external objects by 
means of the senses. There are five senses, namely, Touch, 
Taste, Smell, Hearing, and Vision. 

847. Touch is the sense by which the mind becomes ac- 
quainted with some of the properties of bodies, and enables 
us to determine whether their surfaces are smooth or rough, 
their relative temperature, and, to a certain degree, their form 
and weight. 

848. Some physiologists make a distinction between the 
sense of touch and tact. Tact, or feeling, is more general, 
extending over the whole surface of the skin and mucous 
membranes, while touch exists chiefly in the fingers of man 
and in the noses of certain quadrupeds. 

849. " In the exercise of these functions, tact is considered 
passive ; as, when any part of the system comes into contact 
with another body, a sensation of its presence is given, with- 
out the exercise of volition. On the contrary, touch is active, 
and is exercised voluntarily, for the purpose of conveying to 
the mind a knowledge of the qualities or properties of the 
surfaces of bodies ; as when we feel of a piece of cloth to 
ascertain its qualities, or a polished surface, to prove its 
smoothness." 

850. In man, the hand is admirably adapted to the exercise 

846. Define sensation. How many senses have we ? 847 — 851. What is 
said of the sense of touch f 847. Define touch. 848. "What is the difference 
between touch and tact ? 849. In the exercise of these functions, which is 
active, and which passive ? 850. Why is the hand so admirably adapted 
to the exercise of the sense of touch ? 



HYGIENE OF THE SENSE OF TOUCH. 379 

of touch. " The fineness of the skin, its great sensibility, the 
species of cushion formed by the sub-cutaneous fat at the 
extremities of the fingers, the length and flexibility of these 
organs, and the capability of opposing the thumb to the fingers, 
like a pair of forceps, are so many conditions essentially favor- 
able to the delicacy of this sense, and enable us to appreciate 
with exactitude the qualities of the bodies we may feel." 

851. The nerves that supply the sense of touch, proceed 
from the anterior half of the spinal cord. Where this sense 
is most acute and delicate, we find the greatest number of 
sensitive nervous filaments, and those of the largest size. 

Observation. In amputating limbs, and other surgical oper- 
ations, the division of the skin causes more pain than all the 
subsequent steps of the operation, however protracted. The 
muscles, cellular membrane, and fat have but little sensibility ; 
while the bones, tendons, and ligaments are insensible when 
not diseased, and may be cut without causing pain. 

HYGIENE OF THE SENSE OF TOUCH. 

852. The sense of touch varies in different persons, and 
also in individuals of different ages. Thus the sensibilities of 
the child are more acute than those of the aged. Although 
there is an original difference of sensibility from organization, 
still, the function of the nerves of sensation is modified by 
certain influences. 

853. The healthy or unhealthy, active or inactive state of 
the brain, influences the action of the sensitive nerves. In 
sound and perfect sleep, the brain is inactive. In this state, 
ordinary impressions made upon the skin are not observed by 
the sleeping person. Thus the arm may be blistered while 

851. From what do the nerves proceed that supply this sense ? 852 — 
864. Give the hygiene of the sense of touch. 852. Does this sense vary in 
different persons ? 853. Mention a condition of the brain that influences 
the nerves of sensation. , 



380 ANATOMY, PHYSIOLOGY, AND HYGIENE. 

sleeping, when exposed to the warm rays of the sun, and the 
individual will not be aware of it at the time. 

854. If there is compression of the brain, as when the 
skull-bones are depressed, or disease of this organ exists, as 
in severe typhus fever, impressions made upon the nerves of 
the skin will not be noticed. The same is true when the 
mind is engaged in intense thought or study ; heat or cold may 
be so intense as to disorganize the skin, and not to be noticed. 

855. The varying health or condition of the brain usually 
depresses or increases the sensitiveness of the skin. This is 
seen in grief and fear, which diminish, while hope and joy 
increase the impressibility of this tissue. It is not uncommon 
to see the unfortunate insane endure exposure to heat and 
cold with seeming impunity ; whereas it would induce almost 
insupportable suffering to the sane man. Diseases of the 
heart, stomach, and lungs, alter the condition of the brain, 
and modify, to a greater or less degree, the sensitiveness of 
the skin. 

856. The state of the conducting nervous trunks influences 
the nerves of sensation. If a nervous trunk is compressed or 
divided, the parts supplied by nervous filaments from this 
branch, will be insensible to the impressions made upon them, 
and consequently such impressions are not transmitted to the 
brain. 

Observation. When the inside of the arm or lower extrem- 
ities rests upon a hard surface, the nerves may be compressed 
so as to deprive the parts of sensibility. This condition is 
called " numbness." 

857. The quantity of blood supplied to the skin modifies 



854. Mention other conditions that affect these nerves. 855. "What is 
the effect of the varying health or condition of the brain upon the sensi- 
tiveness of the skin ? Give instances of this effect. 856. What is the 
result if a nervous trunk is divided or compressed? How may "numb- 
ness " in the limbs be produced ? 857. Does the quantity of blood supplied 
to the skin affect its sensibility ? 



HYGIENE OF THE SENSE OF TOUCH. 381 

its sensitiveness. If the quantity of blood is diminished, the 
sensibility of the skin will be impaired. This is demonstrated 
by noting the effects of cold upon the cutaneous tissue, the 
application of which contracts the blood-vessels, and drives the 
circulating fluid from this membrane, which is shown by the 
paleness, as well as by the shrivelled appearance of the skin. 
And, if this tissue is wounded while under the influence of 
cold, but little pain will be felt, and this chilling influence may 
be carried so far as not only to deprive the part of sensation, 
but of vitality. 

858. The influence of the blood upon the sensibility of the 
skin, is further demonstrated by the pain experienced when 
chilled extremities are suddenly exposed to heat. The nerves, 
by the sudden dilatation of the contracted blood-vessels, are put 
in vivid and rapid motion, which causes the painful and tingling 
sensation that we experience. In every part of the system, 
sudden changes produce unpleasant sensations, and frequently 
a diseased condition of the organs. 

Observation. When the hands, or other portions of the 
body, are frozen, or severely chilled, safety and c< mfort de- 
mand that circulation be restored to the parts by moderate 
exercise in a cool room. Not unfrequently, the vitality of the 
limb is destroyed by immersing it in hot water or holding it 
near the fire. 

859. The quality of the blood also influences sensation. If 
the brain and other parts of the nervous system receive impure 
blood, their energy is depressed, and the sensibility of the skin 
rendered more or less obtuse. 

860. The condition of the cuticle modifies the impression 
made upon the cutaneous nerves. 1st. When the cuticle has 

How is it demonstrated ? 858. How is the influence of the blood xipon 
the skin further demonstrated ? How should circulation be restored to 
limbs frozen or severely chilled ? What should be avoided ? 859. Show 
how the quality of the blood influences sensation. 860. Give the 1st condi- 
tion of the cuticle that influences the impressions made on the cutaneous 
nerves. 



382 ANATOMY, PHYSIOLOGY, AND HYGIENE. 

become thick and hard, like horn, as on the inside of the 
mason's hand, it enables him to ply his tools without much 
suffering, because the thickened cuticle diminishes the impres- 
sions made upon the nerves. 

861. 2d. When the cuticle is very thin and delicate, as on 
the hand of the lady who is unaccustomed to manual labor. Let 
her pursue some manual employment for several hours, and 
the extreme tenuity, or thinness of the cuticle, will not protect 
the nerves and parts below from becoming irritated and 
inflamed. 

862. 3d. When the cuticle is removed by blistering or 
abrasion, the pain indicates that the naked nerves are too 
powerfully stimulated by the contact of external bodies. 
4th. When the cuticle is coated with impurities, blended with 
the secretion from the oil-glands, the sensibility of the skin 
is lessened. 

863. The sensibility of the cutaneous nerves is modified by 
being habituated to impressions. If, for example, an indi- 
vidual should immerse his feet in moderately warm water, at 
first it mi s ht induce a smarting sensation ; in a short time, the 
nerves would not only become habituated to the warm water, 
but its warmth might be considerably increased. The same 
results follow, if an individual is exposed to a cold element. 
The impressions at first are highly disagreeable ; but as soon 
as the nerves become accustomed to the surrounding atmos- 
phere, it may impart the most agreeable sensations. 

Illustration. 1st. Let a person from the tropical regions go 
to a colder climate, and the cool mornings of the latter will at 
first affect him unpleasantly ; but, after a few days' exposure 
to the cooler air, the sensation will be far from disagreeable. 

2d. Let a person enter a room moderately heated ; grad- 
ually increase the temperature, until it attains extreme sum- 

861. The 2d condition. 862. The 3d and 4th condition. 863. Show how- 
habit influences the sensibility of the cutaneous nerves. Give illustration 
1st. Illustration 2d. 



HYGIENE OF THE SENSE OF TOUCH. 383 

mer heat ; not only the cutaneous nerves, but the whole 
system, become habituated to the high temperature. From 
these facts we learn that the sensations, are not always a correct 
index of the real temperature. A well-adjusted thermometer 
will indicate it with unerring certainty. 

864. Touch is modified, in a high degree, by education. 
Thus the blind, whose " windows of the soul " are closed to 
the beauties of the external world, cultivate this sense to such 
a degree that they can distinguish objects with great accuracy. 
And the rapidity with which they read books prepared for 
their use, is a convincing proof of the niceness and extent to 
which the cultivation of this sense can be carried. 

Illustrations. 1st. The cloth-dresser, by the aid of this 
sense, distinguishes the quality, as well as the slightest differ- 
ence of texture, in the different pieces of cloth. 

2d. The miller, from a similar education, quickly detects the 
quality of flour or meal, by permitting it to pass between his 
fingers. The difference in the texture of cloths, or the quality 
of the flour, would not be distinguished by an individual whose 
tactile sense had not been trained to make nice comparisons. 



864. Is this sense susceptible of improvement ? What persons cultivate 
it to a high degree ? Give illustration 1st. Illustration 2d. 



382 ANATOMY, PHYSIOLOGY, AND HYGIENE. 

become thick and hard, like horn, as on the inside of the 
mason's hand, it enables him to ply his tools without much 
suffering, because the thickened cuticle diminishes the impres- 
sions made upon the nerves. 

861. 2d. When the cuticle is very thin and delicate, as on 
the hand of the lady who is unaccustomed to manual labor. Let 
her pursue some manual employment for several hours, and 
the extreme tenuity, or thinness of the cuticle, will not protect 
the nerves and parts below from becoming irritated and 
inflamed. 

862. 3d. When the cuticle is removed by blistering or 
abrasion, the pain indicates that the naked nerves are too 
powerfully stimulated by the contact of external bodies. 
4th. When the cuticle is coated with impurities, blended with 
the secretion from the oil-glands, the sensibility of the skin 
is lessened. 

863. The sensibility of the cutaneous nerves is modified by 
being habituated to impressions. If, for example, an indi- 
vidual should immerse his feet in moderately warm water, at 
first it mi .ht induce a smarting sensation ; in a short time, the 
nerves would not only become habituated to the warm water, 
but its warmth might be considerably increased. The same 
results follow, if an individual is exposed to a cold element. 
The impressions at first are highly disagreeable ; but as soon 
as the nerves become accustomed to the surrounding atmos- 
phere, it may impart the most agreeable sensations. 

Illustration. 1st. Let a person from the tropical regions go 
to a colder climate, and the cool mornings of the latter will at 
first affect him unpleasantly ; but, after a few days' exposure 
to the cooler air, the sensation will be far from disagreeable. 

2d. Let a person enter a room moderately heated ; grad- 
ually increase the temperature, until it attains extreme sum- 

861. The 2d condition. 862. The 3d and 4th condition. 863. Show how 
habit influences the sensibility of the cutaneous nerves. Give illustration 
1st. Illustration 2d. 



HYGIENE OF THE SENSE OF TOUCH. 383 

mer heat ; not only the cutaneous nerves, but the whole 
system, become habituated to the high temperature. From 
these facts we learn that the sensations, are not always a correct 
index of the real temperature. A well-adjusted thermometer 
will indicate it with unerring certainty. 

864. Touch is modified, in a high degree, by education. 
Thus the blind, whose " windows of the soul " are closed to 
the beauties of the external world, cultivate this sense to such 
a degree that they can distinguish objects with great accuracy. 
And the rapidity with which they read books prepared for 
their use, is a convincing proof of the niceness and extent to 
which the cultivation of this sense can be carried. 

Illustrations. 1st. The cloth-dresser, by the aid of this 
sense, distinguishes the quality, as well as the slightest differ- 
ence of texture, in the different pieces of cloth. 

2d. The miller, from a similar education, quickly detects the 
quality of flour or meal, by permitting it to pass between his 
fingers. The difference in the texture of cloths, or the quality 
of the flour, would not be distinguished by an individual whose 
tactile sense had not been trained to make nice comparisons. 



864. Is this sense susceptible of improvement ? What persons cultivate 
it to a high degree ? Give illustration 1st. Illustration 2d. 



384 ANATOMY, PHYSIOLOGY, AND HYGIENE. 



CHAPTER XLII. 

SENSE OF TASTE. 

865. The chief organ of taste is the upper surface of the 
tongue ; though the lips, the palate, the internal surface of 
the cheeks, and the upper part of the oesophagus, participate 
in this function. 

ANATOMY OF THE ORGANS OF TASTE. 

866. The tongue is a double organ, composed chiefly of 
muscular fibres, which run in almost every direction. The 
two sides are so perfectly distinct, that sometimes, in paralysis, 
one side is affected, while the function of the other remains 
perfect. It possesses great versatility of motion, and can be 
moulded into a great variety of shapes. In articulation, 
mastication, and deglutition, the tongue is an auxiliary to 
other organs. 

867. This organ is abundantly supplied with blood-vessels, 
having a large artery sent to each side of it. It is also very 
largely furnished with nerves ; it receives nervous filaments 
from the fifth, ninth, and twelfth pairs of nerves. The branch 
of the fifth, called the gustatory, is the nerve of taste and 



865. What is the chief organ of taste ? "What other parts participate 
in the function ? 866 — 870. Give the anatomy of the organs of taste. 
866. Give the structure of the tongue. 867. Is this organ abundantly- 
supplied with blood ? From what source does the tongue derive its 
nerves ? 



\ 



ANATOMY OF THE ORGANS OF TASTE. 



385 



sensibility;* the twelfth, called the hypo-glossal, of voluntary 
motion. By means of the ninth, called the glosso-pharyngeal, 
the tongue is brought into association with the fauces, oesoph- 
agus, and larynx. It is of obvious importance that these 
parts should act in concert ; and this is effected by the distri- 
bution of this nerve. 

Fig. 134. 




Fig. 134. A view of one side of the neck, showing the nerves of the tongue. 
1, A fragment of the temporal bone. 2, 3, 4, 6, 7, 8, 9, 10, 11, 12, Muscles of the 
tongue, fauces, and neck. 5, The tongue. 13, The common carotid artery. 14, The 
jugular vein. 15, The external carotid. 16, The internal carotid. 17, The gustatory 
branch of the fifth pair of nerves. 20, The glosso-pharyngeal nerve. 21, The hypo- 
glossal, or the muscuiar nerve of the tongue. 24, The pneumogastric nerve. 25, The 
facial nerve. 

868. The surface of the tongue is thickly studded with 



* Some physiologists impute the sense of taste to the ninth pair 
of nerves ; others, to the twelfth pair ; while others, again, contend 
that taste is the result of a concurrent action of the fifth, ninth, and 
twelfth pairs of nerves. 

868. What is the appearance of the surface of the tongue ? Explain 
fig. 134. 

33 



386 ANAT0B1Y, PHYSIOLOGY, AND HYGIENE. 

fine papillae, or villi, which give the organ a velvety appear- 
ance. These papilla? are of three varieties. The first is 
situated near the base of the tongue. They belong to the 
class of mucous follicles. They are larger than the others, 
and are called len-tic 1 u-1 ar , from being shaped like a lens. 
These, together with the tonsils, (sometimes called the almonds 
of the ears,) secrete mucus, to lubricate the food in the act 
of deglutition. 

869. The instruments of taste are the two other sets of 
papilla?. One set consists of small, oval-shaped bodies, which 
are scattered over the whole surface of the tongue. They 
give it a rough appearance, and are called the Jil'i-form 
papilla?. 

870. The other set of papilla? is called the fun'gi-form. 
They are larger than the former, and consist of small, 
rounded heads, supported on short stalks, something in the 
shape of mushrooms, from which they derive their name. 
In the last two described sets of sensitive papilla?, the gustatory 
branch of the fifth pair of nerves ramifies. 

Observation. By applying strong acids, as vinegar, to the 
tongue, with a hair pencil, these points will become curiously 
lengthened. 

PHYSIOLOGY OF THE ORGANS OF TASTE. 

871. Taste is the .sense which makes us acquainted with 
the savor of substances. When fluids are taken into the 
mouth, the papilla? dilate and erect themselves, and the par- 
ticular sensation excited is transmitted to the brain through 



How many varieties of papilloe ? Describe the first variety. "What 
is the function of the lenticular papillae ? 869. Describe the filiform 
papilla?. 870. The fungiform papillae? What nerve ramifies in the fun- 
giform papilla? ? How can these papillae, or points, be seen ? 871 — 875 
Give the physiology of tlie organs of taste. 871. Define taste. 



PHYSIOLOGY OF THE ORGANS OF TASTE. 387 

filaments of the gustatory nerve. This sense is closely- 
connected with that of smell. The pleasures derived from 
it are strictly sensual and corporeal, and contribute in no 
way to the expansion of the mind, like those of hearing and 
seeing. 

872. If dry, solid food is taken, the tongue carries it to 
the back side of the mouth, where it receives secretions from 
the salivary glands ; the saliva, becoming impregnated with 
its flavor, flows over the sides of the tongue, and gives to the 
papillae a perception of the savory juice ; this sensation is 
then communicated to the brain. 

Observation. It is supposed that the salts which enter into 
the composition of the saliva, are very efficient agents in 
reducing substances to a proper state for making impressions 
on the nerves of taste. In this way we can account for the 
fact that metals impart a peculiar taste, although they are 
insoluble in water. 

873. The primary use of taste is to guide animals in the 
selection of food, and to warn them against the introduction 
of noxious articles into the stomach. In all the inferior ani- 
mals, we see that the original design of taste is still answered. 
But, in man, this sense has been so abused and perverted, by 
the introduction of stimulants and condiments, and the end- 
less admixture of different articles of food, that the simple 
action of this part seems to have been superseded almost 
entirely by acquired taste. 

874. In children, this sense is usually acute, and their 
preference is for food of the mildest character. And it is 
also true, that every person has some peculiarities of taste, 



With what sense is this closely connected ? What is said of this 
sense ? 872. Give the process by which we taste substances. How can we 
account for the taste of metals when applied to the tongue ? 873. What 
is the primary use of taste ? Where do we see it perverted ? 874. How 
is this sense in children ? What is true of every person in reference to 
taste ? 



388 ANATOMY, PHYSIOLOGY, AND HYGIENE. 

or dislikes to particular articles of food. This may be either 
constitutional or from the influence of association. 

Observation. This sense has been made to vary more than 
any other by the refinements of social life. Thus, the Indian's 
like or dislike to particular kinds of food, generally extends 
to every person of the same tribe ; but among civilized men, 
no two individuals can be found alike in all their tastes. 

875. This sense is modified by habit, and not unfrequently 
those articles, which at first were disgusting, become highly 
agreeable by persevering in the use of them. By cultiva- 
tion, this sense may be made very acute. Those persons 
whose business leads them to judge of the quality of an 
article by their taste, can discriminate shades of flavor not 
perceivable by ordinary persons. Epicures, and tasters of 
wines and teas, afford examples. 

Observation. Many persons impair their taste by bad 
habits, as chewing and smoking tobacco, and using stimu- 
lating drinks, and pungent condiments with the food. These 
indulgences lessen the sensibility of the nerve, and destroy 
the natural relish for food. 

What is true of the Indian ? 875. Is this sense modified by habit ? Give 
instances. How is this sense sometimes impaired ? 



ANATOMY OF THE ORGANS OF SMELL. 380 

CHAPTER XLIII. 

SENSE OF SMELL. 

876. This sense is located in the air-passages of the Nose. 
To understand the function of smell, the structure of the nose 
and nasal cavities, with the distribution of the olfactory nerves, 
must be first examined. 

ANATOMY OF THE ORGANS OF SMELL. 

877. The nose is composed of the Bones, Fi'bro-car'ti- 
lages, and Mu'cous Mem'brane, together with its integuments. 

878. The bones of the nose are the nasal, and the nasal 
processes of the upper jaw. 

879. The fibro-cartilages give form and stability to the 
framework of the nose, providing at the same time, by their 
elasticity, against injuries. They are five in number. 

880. The mucous membrane, which lines the interior of 
the nose, is continuous with the skin externally, and with the 
lining membrane of the parts of the throat. The entrance of 
the nostrils is provided with numerous hairs, which serve as 
guardians to the delicate membrane of the nose. 

881. The nasal fossae, or nostrils, are two irregular, com- 
pressed cavities, extending from the nose to the pharynx. 
These cavities are bounded superiorly by the sphenoid and 



876. Where is the sense of smell located ? 877 — 884. Give the anatomy 
of the organs of smell. 877. Name the parts that enter into the structure 
of the nose ? 878. What bones form the framework of the nose ? 
879. What is the use of the cartilages ? 880. What relation has the 
mucous membrane with other membranes of the nose ? 881. Describe 
the nasal cavities. 

S3* 



390 



ANATOMY, PHYSIOLOGY, AND HYGIENE. 



ethmoid bones ; inferiorly, by the hard palate. In the middle 
line they are separated from each other by a bony and fibro- 
cartilaginous septum ; upon the outer wall of each fossa, in 
the dried skull, are three projecting processes, termed spongy 
bones. In the fresh fossa, these are covered by a. mucous 
membrane. 

882. The space that intervenes between the superior and 
middle spongy bone, is called the superior me-a'tus, or chan- 
nel ; the space between the middle and inferior bone, is the 
middle meatus ; and that between the inferior bone and the 
floor of the fossa, is the inferior meatus. 

Fig. 135. 




Fig. 135. A vertical section of the middle part of the nasal cavities. 7, The 
middle spongy bones. 8, The superior part of the nasal cavities. 10, The inferior 
spongy hones. II, The vomer. 12, The upper jaw. 13. The middle channel of the 
nose. 14, The lower channel of the nose. 17, The palatine process of the upper jaw- 
bone. 18, The roof of the mouth covered by mucous membrane. 19, A section of 
this membrane. 

883. The meatuses are passages that extend backward, 
into which are several openings. They are lined by a mucous 
membrane, called the pi-tu'i-ta-ry, or schneiderian, from 



882. What terms are applied to the spaces between these processes ? 
"What does fig. 135 represent ? 883. Define the meatuses. By what are 
they lined ? • 



PHYSIOLOGY OF THE ORGANS OF SMELL. 



391 



Schneider, who first showed that the secretion of the nasal 
fossae proceeded from the mucous membrane, and not from 
the brain. 

884. Upon the mucous membrane of the nasal passages, 
the olfactory nerve ramifies, and also a branch of the fifth 
pair of nerves. This membrane is of considerable extent in 
man ; and in those animals whose sense of smell is very- 
acute, it is still more extensive. 




Fig. 136. A side view of the passage of the nostrils, and the distribution of ths 
olfactory nerve. 4, The olfactory nerve. 5, The fine and curious divisions of this 
nerve ou the membrane of the nose. 6, A branch of the fifth pair of nerves. 



PHYSIOLOGY OF THE ORGANS OF SMELL. 

885. The sense of srrfell enables us to discern the odor or 
scent of any thing. When substances are presented to the 
nose, the air that is passing through the nostrils brings the 
odoriferous particles of matter in contact with the filaments 
of the olfactory nerves, that are spread upon the membrane 



884. What nerves ramify upon this membrane ? "What is represented by 
fig. 136? 885 — 899. Give the physiology of the organs of smell. 885. How 
does the mind become sensible of odoriferous particles ? 



392 ANATOMY, PHYSIOLOGY, AND HYGIENE. 

that lines the air-passages, and the impression is then trans- 
mitted to the brain. 

886. This sense, with that of taste, aids man as well as the 
inferior animals, in selecting proper food, and it also gives us 
pleasure by the inhalation of agreeable odors. The sense of 
smell, like that of taste and touch, may be improved by cul- 
tivation. It likewise varies in different persons. 

Observation. Sometimes this sense seems to possess a 
morbid degree of acuteness in respect to odors, which is highly 
inconvenient and even dangerous. With some individuals, the 
smell of certain fruits, flowers, cheese, &c, produce nausea 
and even convulsions. 

887. In the inferior animals generally, the sense of smell 
is more acute than in man. Thus the bloodhound will trade 
the hare over the ground for miles, guided only by the odor 
that it leaves in its flight. He also traces the progress of 
his master through thickly-crowded streets, distinguishing his 
footsteps from those of a thousand others, and amidst the 
odorous particles emanating from a thousand sources. 

Observation. In some of the higher orders of the inferior 
animals, there is an astonishing acuteness of smell in regard to 
effluvia that come from living animals. To these animals, it 
possesses an importance in them far beyond what it has in 
man, by making them acquainted with the presence of their 
enemies or their prey, when the eye and ear are incapable 
of acting. It is related by travellers in Africa, that they were 
always apprised of lions in their vicinity during the night, by 
the moans and tremblings of their horses. 

888. Smell is somewhat under the control of the will. That 



886. What is the use of the sense of smell? Can this sense be im- 
proved by cultivation ? "What is said respecting this sense in some 
individuals ? 887. What is said of this sense in the bloodhound ? Men- 
tion an instance of astonishing acuteness of smell in some of the higher 
orders of animals. 888. Show that smell is somewhat under the control 
of the will. 



PHYSIOLOGY OF THE ORGANS OF SMELL. 393 

is, we have the power of receiving or rejecting odors that are 
presented ; thus, if odors are agreeable, we inspire forcibly, to 
enjoy them ; but, if they are offensive, our inspirations are 
more cautious, or we close our nostrils. This sense is like- 
wise modified by habit ; odors which, in the first instance, 
were very offensive, may not only become endurable, but 
even agreeable. 

889. Acuteness of smell requires that the brain and nerve 
of smell be healthy, and that the membrane that lines the nose 
be thin and moist. Any influence that diminishes the sensi- 
bility of the nerves, thickens the membrane, or renders it dry, 
impairs this sense. 

Observations. 1st. Snuff, when introduced into the nose, 
not only diminishes the sensibility of the nervous filaments, 
but thickens the lining membrane. This thickening of the 
membrane obstructs the passage of air through the nostrils, 
and thus obliges " snuff-takers " to open their mouths when 
they breathe. 

2d. The mucous membrane of the nasal passages is the 
seat of chronic catarrh. This affection is difficult of removal, 
as remedial agents cannot easily be introduced into the wind- 
ings of these passages. Snuff and many other articles used 
for catarrh, produce more disease than they remove. 



889. On what does acuteness of smell depend ? "What effect has snuff 
when introduced into the nose ? What is said of chronic catarrh ? 



394 ANATOMY, PHYSIOLOGY, AND HYGIENE. 



CHAPTER XLIV. 

SENSE OE VISION. 

890. This sense contributes more to the enjoyment and 
happiness of man than any other of the senses. By it we 
perceive the form, color, volume, and position of objects that 
surround us. The eye is the organ of sight, or vision, and its 
mechanism is so wonderful, that it not only proves the exist- 
ence of a great First Cause, but perhaps, more than other 
organs, the design of the Creator to mingle pleasure with our 
existence. 

ANATOMY OF THE ORGANS OF VISION. 

891. The apparatus of vision consists of the Optic Nerve, 
the Globe and Muscles of the eye, and its Protecting Organs. 

892. The optic nerve arises by two roots from the cen- 
tral portion of the base of the brain. The two nerves approach 
each other, as they proceed forward, and some of the 
fibres of each cross to the nerve of the opposite side. They 
then diverge, and enter the globe of the eyes at their back 
part, where they expand, and form a soft, whitish membrane. 

893. The globe, or ball of the eye, is an optical instru- 
ment of the most perfect construction. The sides of the globes 
are composed of Coats, or membranes. The interior of the 
globe is filled with refracting Humors, or me'di-ums. 



899. "Which sense contributes most to the enjoyment of man ? What do 
we perceive by this sense ? "What is said of the mechanism of the eye ? 
891 — 916. Give the anatomy of the organs of vision. 891. Of what does the 
apparatus of vision consist ? 892. Describe the optic nerve. 893. Describe 
the globe of the eye. 



ANATOMY OF THE ORGANS OF VISION. 



395 



894. The coats are three in number : 1st. The Scle- 
rotic and Corn'e-a. 2d. The Cho'roid, Iris, and Cil'ia-ry 
processes. 3d. The Ret'i-na. 

895. The humors are also three in number : 1st. The 
A'que-ous, or watery. 2d. The Crys'tal-Une, (lens.) 3d. The 
Vit're-ous, or glassy. 

Fig. 137. 




Fig. 137. The second pair of nerves. 1, 1, Globe of the eye : the one on the left 
is perfect, but that on the right has the sclerotic and choroid coats removed, to show 
the retina. 2, The crossing of the optic nerve. 5, The pons varolii. 6, The me- 
dulla oblongata. 7, 8, 9, 10, 11, 12, 13, The origin of several pairs of cranial nerves. 

896. The sclerotic coat is a dense, fibrous membrane, 
and invests about four fifths of the globe of the eye. It gives 
form to this organ, and serves for the attachment of the mus- 
cles that move the eye in various directions. This coat, from 
the brilliancy of its whiteness, is known by the name of " the 



894. Name the coats of the' eye. 895. Name the humors of the eye.' 
Explain fig. 137. 896. Describe the sclerotic coat. 



396 ANATOMY, PHYSIOLOGY, AND HYGIENE. 

white of the eye." Anteriorly, the sclerotic coat presents a 
bevelled edge, which receives the cornea in the same way that 
a watch-glass is received by the groove in its case. 

897. The cornea is the transparent projecting layer, that 
forms the anterior fifth of the globe of the eye. In form, it 
is circular, convexo-concave, and resembles a watch-glass. 
It is received by its edge, which is sharp and thin, within the 
bevelled border of the sclerotic, to which it is firmly attached. 
The cornea is composed of several concentric layers ; its 
blood-vessels are so small that they exclude the red particles 
altogether, and admit nothing but serum. 

898. The choroid coat is a vascular membrane, of a rich 
chocolate-brown color upon its external surface, and of a deep 
black color within. It is connected, externally, with the scle- 
rotic, by an extremely fine cellular tissue, and by the passage 
of nerves and vessels ; internally, it is in contact with the 
retina. The choroid membrane is composed of three layers. 
It secretes upon its internal surface a dark substance, called 
pig-ment'um ni'grum, which is of great importance in the 
function of vision. 

899. The iris is so called from its variety of color in dif- 
ferent persons. It forms a partition between the anterior and 
posterior chambers of the eye, and is pierced by a circular 
opening, which is called the pu'pil. It is composed of two 
layers. The radiating fibres of the anterior layer converge 
from the circumference to the centre. Through the action of 
these radiating fibres the pupil is dilated. The circular fibres 
surround the pupil, and by their action produce contraction of 
its area. The posterior layer is of a deep purple tint, and is 
called u-ve f a, from its resemblance in color to a ripe grape. 

How are this coat and the cornea united ? 897. Describe the cornea. 
898. What is the color of the external surface of the choroid coat ? Of 
the internal? How is it connected externally? How internally ? What 
does this membrane secrete upon its internal surface ? 899. Describe the 
iris. Of how many layers of fibres is the iris composed ? What is the 
function of the radiating fibres ? Of the circular ? 



ANATOMY OF THE ORGANS OF VISION. 



397 



900. The ciliary processes consist of a number of trian- 
gular folds, formed, apparently, by the plaiting of the internal 
layer of the choroid coat. They are about sixty in number. 
Their external border is continuous with the internal layer of 
the choroid coat. The central border is free, and rests against 
the circumference of the crystalline lens. These processes 
are covered by a layer'of the pigmentum nigrum. 

Pig. 138. 




Fig. 138. A view of the anterior segment of a transverse section of the globe of 
the eye, seen from within. 1, The divided edge of the three coats — sclerotic, cho- 
roid, and retina. 2, The pupil. 3, The iris: the surface presented to view in this 
section being the uvea. 4, The ciliary processes. 5, The scalloped anterior border 
of the retina. 

901. The retina is composed of three layers: The ex- 
ternal ; middle, or nervous ; and internal, or vascular. The 
external membrane is extremely thin, and is seen as a floccu- 
lent film, when the eye is suspended in water. The nervous 
membrane is the expansion of the optic nerve, and forms a 
thin, semi-transparent, bluish- white layer. The vascular 



900. How are the ciliary processes formed ? What does fig. 138 exhibit ? 
901. Of how many layers is the retina composed ? Describe the external 
layer. The nervous layer. 



34 



dyo ANATOMY, PHYSIOLOGY, AND HYGIENE. 

membrane consists of the ramifications of a minute artery and 
its accompanying vein. This vascular layer forms distinct 
sheaths for the nervous papillse, which constitute the inner 
surface of the retina. 

902. The aqueous humor is situated in the anterior and 
posterior chambers of the eye. It is an albuminous fluid, 
having an alkaline reaction. Its specific gravity is a very little 
greater than distilled water. The anterior chamber is the 
space intervening between the cornea, in front, and the iris 
and pupil, behind. The posterior chamber is the narrow 
space, less than half a line in depth, bounded by the posterior 
surface of the iris and pupil, in front, and by the ciliary pro- 
cesses and crystalline lens, behind. The two chambers are 
lined by a thin layer, the secreting membrane of the aqueous 
humor. 

903. The crystalline humor, or lens, is situated imme- 
diately behind the pupil, and is surrounded by the ciliary 
processes. This humor is more convex on the posterior than 
on the anterior surface, and, in different portions of the sur- 
face of each, the convexity varies from their oval character. 
It is imbedded in the anterior part of the vitreous humor, from 
which it is separated by a thin membrane, and is invested by 
a transparent elastic membrane, called the capsule of the lens. 
The lens consists of concentric layers, disposed like the coats 
of an onion. The external layer is soft, and each successive 
one increases in firmness until the central layer forms a hard- 
ened nucleus. These layers are best demonstrated by boiling, 
or by immersion in alcohol, when they separate easily from 
each other. 

Observations. 1st. The lens in the eye of a fish is round, 

The vascular layer. 902. Where is the aqueous humor situated ? What 
part of the eye is called the anterior chamber ? The posterior chamber ? 
With what are the chambers lined ? 9C3. Where is the crystalline humor 
situated ? With what is it surrounded ? Of what does the lens consist ? 
How are these layers best demonstrated ? What is produced when the 
lens, or its investing membrane, is changed in structure ? 



ANATOMY OF THE ORGANS OP VISION. 



399 



like a globe, and has the same appearance, when boiled, as the 
lens of the human eye. 

2d. When the crystalline lens, or its investing membrane, 
is changed in structure, so as to prevent the rays of light pass- 
ing to the retina, the affection is called a cataract. 

Fig:. 139. 




Fig. 139. A section of the globe of the eye. 1, The sclerotic coat. 2, The cornea. 
(This connects with the sclerotic coat by a bevelled edge.) 3, The choroid coat. 
6, 6, The iris. 7, The pupil. 8, The retina. 10, 11, 11, Chambers of the eye that 
contain the aqueous humor. 12, The crystalline lens. 13, The vitreous humor. 
15, The optic nerve. 16, The central artery of the eye. 

904. The vitreous humor forms the principal bulk of the 
globe of the eye. It is an albuminous fluid, resembling the 
aqueous humor, but is more dense, and differs from the aque- 
ous in this important particular, that it has not the power 
of re-producing itself. If by accident it is discharged, the eye 
is irrecoverably lost ; while the aqueous humor may be let out, 
and will be again restored. It is enclosed in a delicate mem- 
brane, called the hy'a-loid, which sends processes into the 
interior of the globe of the eye, forming the cells in which 
the humor is retained. 



904. Describe the vitreous humor. How does this humor differ from the 
aqueous ? What membrane encloses the vitreous humor ? 



400 



ANATOMY, PHYSIOLOGY, AND HYGIENE. 



Observation. The structure of this organ can be seen by 
first freezing the eye of a sheep or an ox ; it then can be cut 
in various directions, and each part separately examined. 

905. The muscles of the eye are six in number. They 
are attached, at one extremity, to the bones of the orbit behind 
the eye ; at the other extremity, they are inserted by broad, 
thin tendons, near the junction of the cornea with the sclerotic 
coat. The white, pearly appearance of the eye is caused by 
these tendons. 

Fig. 140. 




Fig. 140. A view of the eye and its muscles, a, b, c, d, e, Five of these muscles. 
/, The optic nerve. G, The trochlea, or pulley over which one of the muscles passes. 
The bone is seen above and below the eye. 

Observation. If the external muscle is too short, the eye 
is turned out, producing the " wall eye." If the internal 



905. How many muscles has the eye ? Give their attachments. What 
causes the pearly appearance of the eye ? What does fig. 140 represent ? 
What is the effect if the external muscle is contracted ? The internal 
muscle ? 



ANATOMY OF THE ORGANS OF VISION. 401 

muscle is contracted, the eye is turned inward toward the 
nose. It is then called a " cross eye." 

906. The protecting organs are the Orbits, Eyebrows, 
Eyelids, and Lachry-mal Apparatus. 

907. The orbits are deep, bony sockets, in which the 
globes of the eyes are situated. They have the form of a 
cone, the base of which is open and directed forward. The 
bottom of the orbits is pierced by a large hole, which gives 
passage to the optic nerve. These cavities are lined with a 
thick cushion of fat, in order that the eyes may move in all 
directions, with perfect freedom and without friction. 

908. The eyebrows are two projecting arches of integu- 
ment, covered with short, thick hairs, which form the upper 
boundary of the orbits. The eyebrows are so arranged that 
they prevent the moisture that accumulates on the forehead, 
in free perspiration, from flowing into the eye, and also shade 
these organs from too vivid light. 

909. The eyelids are two movable curtains placed in 
front of the eye. They have a delicate skin on the outside, 
muscular fibres beneath, and a narrow cartilage on their edges, 
which tends to preserve the shape of the lid. Internally, they 
are lined by a smooth membrane, which is reflected over the 
front of the eye upon the sclerotica. This membrane is called 
the con-junc-ti'va. It secretes the fluid that moistens and lubri- 
cates the eye, and which causes the eyelids to open and shut 
without friction. 

Observation. When the portion of this membrane that 
is reflected over the globe of the eye, is inflamed, there is 
frequently a deposition of whitish material, called lymph. This 
accounts for the films, opacities, and white spots seen upon 
the eye after the inflammation has subsided. 

906. Name the protecting organs of the eye. 907. Describe the orbits. 
How are the movements of the eye facilitated ? 908. Describe the eye- 
brows. What does this arrangement prevent ? 909. Describe the eyelids. 
"What is the use of the conjunctiva ? How are the white spots frequently 
seen upon the eye accounted for ? 
34* 



402 



ANATOMY, PHYSIOLOGY, AND HYGIENE. 



910. There are found several small glands on the in- 
ternal surface of the cartilage, which have the appearance of 
parallel strings of pearls. They open by minute apertures 
upon the edges of the lids. The secretion from these glands 
prevents the edges of the eyelids from being united during 
sleep. 

911. The edges of the eyelids are furnished with a triple 
row of long, thick hairs, called eyelashes, which curve upward 
from the upper lid, and downward from the lower, so that 
they may not interlace with each other in the closure of the 
eyelids. These appendages of the eye, by closing, not 
only protect it from moisture, but from dust, particularly 
during sleep. They likewise, by their movements in open- 
ing and shutting, spread the lubricating fluid equally over 
the eye. 

912. The lachrymal apparatus, which secretes the tears, 
consists of the Lachrymal Gland with its ducts, Lachrymal 
Canals, and the Nasal Duct. 

913. The lachrymal gland is situated at the upper and 
outer angle of the orbit. It is about three quarters of an inch 
in length, flattened and oval in shape, and occupies a depres- 
sion in the orbital plate of the frontal bone. Ten or twelve 
small ducts pass from this gland, and open upon the upper 
eyelid, where they pour upon the conjunctiva the lachrymal 
fluid, or tears. This secretion is maintained while we are 
asleep, as well as when we are awake. The eye from this 
cause is kept constantly moist. 

914. The lachrymal canals commence at minute open- 
ings upon the free borders of each eyelid, near the internal 



910. "What are found on the internal surface of the cartilage of the eye- 
lids ? Where do they open, and what is their use ? 911. With what are the 
edges of the eyelids furnished? What are their uses ? 912. Of what does 
the lachrymal apparatus consist ? 913. Describe the lachrymal gland. 
How many ducts pass from this gland, and what do they convey to the 
eye ? Why is the eye constantly moist ? 914. Where do the lachrymal 
canals commence ? 



ANATOMY OF THE ORGANS OF VISION. 403 

angle of the eye, by two small orifices, called punc'ta lach-ry- 
ma'li-a, (tear points.) Each of these points communicate 
with the sac at the upper part of the nasal duct. 

915. The nasal duct is a short canal, about three quarters 
of an inch in length, directed downward and backward to the 
inferior channel of the nose,, where it terminates by an ex- 
panded orifice. 

Fie. 141. 




Fig. 141. 1, The lachrymal gland. 2, Ducts leading from the lachrymal gland to 
the upper eyelid. 3, 3, The puncta lachrymalij. 4, The nasal sac. 5, The termi- 
nation of the nasal duct. 

916. The fluid (tears) secreted by the lachrymal gland, is 
conveyed to the eye by the small ducts before described. It 
is then imbibed by the puncta lachrymalia, and carried by the 
lachrymal canals into the lachrymal sac, from which it is 
passed to the nasal cavities by the nasal ducts. 

What are they called ? "With what do they communicate ? 915. De- 
scribe the nasal duct. 916. How are the tears conveyed from the lachrymal 
gland to the nose ? 



404 ANATOMY, PHYSIOLOGY, AND HYGIENE. 



CHAPTER XLV. 

PHYSIOLOGY OF THE ORGANS OF VISION. 

917. To comprehend the theory of vision, it is not suffi- 
cient to know the structure of the eye. We must be familiar 
with some of the properties of a subtile fluid, which is con- 
stantly emanating from all luminous bodies, called light. 

918. It is the province of natural philosophy, rather than 
physiology, to enter minutely upon the properties of light. 
It may be observed, however, that, when light passes through 
any medium of the same density, the rays are in straight 
lines ; but, when it passes from one medium "into another of 
different density, it is refracted, or turned from a straight 
course, unless it strikes the medium in a perpendicular 
direction — then light passes through without a change of 
direction. 

919. When a ray of light meets with a body, it either 
passes through it, or is reflected by it, or it may be absorbed. 
Again, in proportion as the rays of light become distant from 
the body from which they emanate, they diverge one from 
the other. In accordance with the laws of optics, the rays 
of light, in passing through an optical instrument like the eye, 
must cross each other, and thus produce an inverted image 
of the object from which the rays proceed. With the general 



917 — 933. Give the physiology of the organs of vision. 917. "What is neces- 
sary in order to understand the theory of vision ? 918. When light passes 
through a medium of the same density, in what direction will be its rays ? 
Of a different density ? "What exception ? 919. When light meets with 
a body, what takes place ? "What is said in reference to rays of light in 
passing through the eye ? 



PHYSIOLOGY OF THE ORGANS OF VISION. 405 

view of the structure of the eye, we will now examine the 
use of each part in the function of vision. 

920. The sclerotic coat not only gives form to the body 
of the eye, but protection to the interior and more delicate 
parts. The choroid coat seems to be chiefly composed of a 
tissue of nerves and minute blood-vessels ; the latter give 
nourishment to the different parts of the eye. One of the 
»uses of this coat is, to absorb the rays of light immediately 
after they have passed through the retina. This is effected 
by the black pigment that lines its inner surface. Were it 
not for this provision, light would be too intense, and vision 
indistinct. 

Observation. In albinos, where there is an absence of the 
black pigment, the rays of light traverse the iris, and even 
the choroid coat, and so overwhelm the* eye with light, that 
their vision is quite imperfect, except in the dimness of 
evening, or at night. In the manufacture of optical instru- 
ments, care is taken to color their interior black, for the same 
object, namely, the absorption of scattered rays. 

921. The iris, by means of its powers of expansion and 
contraction, regulates the quantity of light admitted through 
the pupil. If the iris is thin, and the rays of light pass 
through its substance, they are immediately absorbed by the 
uvea, and, if that layer be insufficient, they are taken up by 
the black pigment of the choroid coat. 

Observation. When we look toward the bottom of the eye, 
the pupil appears like a black spot, instead of an opening. 
This is caused by seeing the black pigment through the retina 
and humors of the eye. 



920. What is the use of the sclerotic coat ? Of what is the choroid 
coat chiefly composed ? What is the use of this coat ? How is it effected ? 
"What is said of albinos ? What care is taken in the manufacture of 
optical instruments ? 921. What is the Use of the iris ? When we look 
toward the bottom of the eye, why does the pupil look like a black spot, 
instead of an opening ? 



406 ANATOMY, PHYSIOLOGY, AND HYGIENE. 

922. The cornea, and the aqueous, crystalline, and vitreous 
humors, are transparent ; so that rays of light traverse these 
parts of the eye, and fall upon the retina. The office of 
these humors and the cornea is to refract the rays of light in 
such proportion as to direct the image in the most favorable 
manner upon the retina. 

923. The office of the retina is to receive the impression 
of the rays of light which leave an object at which we look, 
and it is upon it that a small but very clear image of that 
object is formed. The impression thus produced is trans- 
mitted by the optic nerve to the brain, which receives the 
sensation. This constitutes vision. 

924. The optic nerve has but one function, that of sight. 
Sensibility is conferred on this organ by a large branch from 
the fifth pair of norves, which ramifies upon the different 
parts of the eye and its appendages. These parts, however, 
receive some nervous filaments from the seventh pair. 

Observations. 1st. The large number of sensitive ner- 
vous filaments renders the visual organ very impressible to 
bodies that cause irritation, as dust, or intense light. This 
compels us to use due care to shield the eye from the influ- 
ence of agents that would impair or destroy vision. 

2d. Although particles of dust, when in contact with the 
delicate parts of the eye, induce severe pain, yet these parts 
may be cut in surgical operations, and the patient's sufferings 
are not as great as when an incision is made in the skin to 
remove a small tumor. 

925. Different degrees of density, as already mentioned, 
modify the refractory power of any transparent medium. It 
is found, on examination, that the cornea, the vitreous, the 



922. "What is the use of the cornea, aqueous, crystalline, and vitreous 
humors? 923. What is the office of the retina? 924. What is the 
function of the optic nerve ? How is sensibility conferred on this organ ? 
Give the 1st observation in this connection. The 2d observation. 



PHYSIOLOGY OF THE ORGANS OF VISION. 



407 



crystalline, and the aqueous humors, have each, severally, 
various degrees of density ; and that the crystalline lens, at 
its circumference, is more dense than at its centre. These 
circumstances modify the direction of the refraction of the 
rays of light, in their passage from the cornea to the retina. 

926. The refracting powers of the plane, convex, concave, 
plano-convex, plano-concave, and concavo-convex lenses,* 
are different. The cornea and aqueous humors are convexo- 
concave, the vitreous humor is concavo-convex, while the 
crystalline humor is a convexo-convex medium. (Fig. 139.) 




Fig. 142. The forms of the different lenses. 1, A plane lens. 2, A globe lens. 
3, A convexo-convex lens. 4, A plano-convex lens. 5, A concavo-concave lens. 
6, A plano-concave lens. 7, Meniscus. 8, A concavo-convex lens. 

927. The different degrees of convexity or concavity also 
modify the refracting character of transparent mediums. 
The crystalline lens is of different degrees of convexity on 
its two sides. The convex surfaces of the aqueous and 
vitreous humors are segments of circles, of different diame- 
ters from their concave surfaces. (Fig. 139.) All these 



* The refracting character of differently-formed lenses is illustrated 
in the works on Natural Philosophy, to which the pupil is referred. 



925. Have the cornea and the humors of the eye different degrees of 
density ? "What is said of the crystalline lens ? What effect has the 
different density of the parts of the eye upon the light admitted to this 
organ ? 926. What kind of lenses do the humors exhibit ? 927. What 
modifies the refracting powers of transparent mediums ? How does this 
principle apply to the humors of the eye ? 



408 ANATOMY, PHYSIOLOGY, AND HYGIENE. 

circumstances still further influence the refracting charac- 
ter of the visual organ. The achromatic arrangement of 
the transparent refracting mediums of the eye, remedies 
the aberration of refraction in the different portions of the 
eye. 

928. Again, the refracting power of lenses is modified by 
their convexity or concavity. The more convex a lens is, 
the shorter the distance from the refracting medium, where 
the different refracted rays converge to a focus. To adapt 
the eye to view objects at different distances, requires a 
change in the refracting power of some of the transparent 
mediums of the eye. 

929. Both surfaces of the crystalline lens are oval, not 
spherical, and the refraction of the rays of light is mainly 
effected in this portion of the eye. Change the inclination 
of this lens, so that different portions of its anterior surface 
shall be directly behind the pupil, and its refracting power is 
increased or diminished, as the surface presented is more or 
less convex. 

930. To view objects at a distance, a more convex lens is 
needed than in examining articles very near the eye ; and 
this organ, from its structure, has the power of adaptation to 
different distances. The action of the ciliary processes 
changes the inclination of the crystalline lens, which modifies 
the refraction of rays of light proceeding from objects to 
which the eye is directed. Without this, or some other 
adapting power, a picture of objects at different distances 
would not be formed upon the retina, and the vision of every 
person would be defective, except in reference to objects at 
certain definite distances from the eye. 

928. What modifies the refracting power of lenses ? What is necessary 
to adapt the eye to view objects at different distances ? 929. Where is the 
refraction of the rays of light mainly effected ? 930. When we view 
objects at a distance, what kind of lens is required ? Has the eye the 
power of adapting itself to different distances ? How is it effected ? 



PHYSIOLOGY OF THE ORGANS OF VISION. 409 

Observation. It is well known that a separate image is 
formed on each eye, and, if they are not in the same direc- 
tion, the objects will appear double. This is proved by 
pressing one eye, so that the rays of light cannot enter it in 
the same direction as they do in the other ; consequently, the 
vision is double. 

931. By the action of the muscles of the eye, it is turned 
in different directions, so that objects can be examined upon 
each side, as well as in front, without turning the body. By 
the slight or intense action of the straight muscles, the eye is 
more or less compressed, and the form of the globe is 
changed, together with the relative positions of the different 
humors. This modification also adapts the eye to view ob- 
jects at different distances. 

Fig. 143. 




Fig. 143. 1, A pen, an inverted image of which is painted on the retina of the 
eye, at 2. The image of all objects upon the expansion of the optic nerve, is inverted 
by the crossing of the rays of light from objects as they traverse the pupil. 

Observation. If the eye is fixed for a time on some object 
which is distinguished with difficulty, there is a painful sensa- 
tion, similar to that experienced by other muscles of the body 
when used too long. This is called " straining the eye." 

932. When the refraction of the rays of light is too great, 
as in over-convexity of the cornea, or the crystalline lens, or 
the vitreous humor, or all of them, the image is formed a 

"What does fig. 143 represent ? 931. "Why can we see objects at the side 
as well as in front of the eye, without turning the body ? What is the 
effect when the eye is fixed on an object that is indistinctly seen ? 
35 



410 ANATOMY, PHYSIOLOGY, AND HYGIENE. 

little in front of the retina. Persons thus affected cannot see 
distinctly, except at a very short distance. This infirmity 
is called near, or short-sightedness. This defect is in a great 
measure obviated by the use of concave glasses, which scatter 
the luminous rays, and thus counterbalance the too strong 
refracting force of the eye. 

933. When the different parts of the eye are not sufficient- 
ly convex, the image is formed beyond the retina, and thus 
only distant objects are distinctly seen. This defect is called 
long-sightedness. The feebleness in the refracting power of 
the eye may be caused by disease ; but usually it is a conse- 
quence of old age, and is remedied by wearing spectacles 
with convex glasses. 



HYGIENE OF THE ORGANS OF VISION. 

934. The eye, like other organs of the body, should be 
used, and then rested. If we look intently at an object for 
a long time, the eye becomes wearied, and the power of 
vision diminished. The observance of this rule is particular- 
ly needful to those whose eyes are weak, and predisposed to 
inflammation. On the contrary, if the eye is not called into 
action, its functions are enfeebled. 

935. Sudden transitions of light should be avoided. The 
iris enlarges or contracts, as the light that falls upon the eye 
is faint or strong : but the change is not instantaneous. 



932. "What is short-sightedness ? How is the defect remedied ? 933. "What 
is long-sightedness ? How is the defect remedied ? 934 — 942. Give the 
hygiene of the organs of vision. 93-1. Do the same principles apply to the 
use of the eye as to other organs ? What is the effect if the eye is fixed 
intently on an object for a long time? "What results if the eye is not 
called into action ? 935. Why should sudden transitions of light he 
avoided ? 

Note. Let the anatomy and physiology of the eye be reviewed from 
figs. 139 and 143, or from anatomical outline plate No. 10. 



HYGIENE OF THE ORGANS OF VISION. 411 

Hence the imperfect vision in passing from a strong to a dim 
light, and the overwhelming sensation experienced on emerg- 
ing from a dimly-lighted apartment to one brilliantly illu- 
minated. A common cause of am-aur-o'sis, or paralysis of 
the retina, is, using the eye for a long time in a very intense 
light. 

936. Long- continued oblique positions of the eye should be 
avoided, when viewing objects. If the eye is turned obliquely 
for a long time in viewing objects, it may produce an unnat- 
ural contraction of the muscle called into action. This con- 
traction of the muscle is termed stra-bis'mus, or cross-eye. 
The practice of imitating the appearance of a person thus 
affected, is injudicious, as the imitation, designed to be tem- 
porary, may become permanent. 

Observation. The vision of a " cross-eye " is always 
defective. In general, only one eye is called into action, in 
viewing the object to which the mind is directed. This 
defect can be remedied by a surgical operation, which also 
corrects the position of the eye. 

937. Children should be trained to use the eye upon objects 
at different distances. This is necessary, in order that the 
vision may be correct when objects at various distances are 
viewed. Any action unnatural to the muscles, if frequently 
repeated, may and will modify the character and action of 
the parts so operated upon. If a limb, as the arm, be kept 
flexed for a long time, one set of muscles will be relaxed and 
elongated, and another will be shortened, and its contractile 
power will be increased. The same principle is true of 
the eye. 

What causes palsy of the retina ? 936. Why should we avoid oblique 
positions of the eye in viewing objects ? "What is said of the practice of 
imitating persons thus affected ? What is said in reference to the vision 
of a " cross-eye " ? 937. Why should children be trained to use the eye 
upon objects at different distances ? What is the effect if an unnatural 
action of the muscles is frequently repeated ? Does the same principle 
apply to the eye ? 



412 ANATOMY, PHYSIOLOGY, AND HYGIENE. 

938. In viewing objects very near the eye, the ciliary 
processes are called into action to produce a proper inclina- 
tion of the crystalline lens, so that the rays of light may be 
properly refracted to form a perfect image on the retina. In 
looking at objects at a great distance, the ciliary processes 
are called into a different action, to produce a different in- 
clination of the lens. Let either of these actions be repeated, 
again and again, for weeks and months, and they will become 
natural, and the acquired inclination will be permanent. 

939. From the preceding principle, a person becomes 
short or long sighted, as the objects to which the eye is usually 
directed are near or remote. This is one reason why scholars, 
watchmakers, and artisans, who bring minute objects near the 
eye to examine them, are short-sighted, and why hunters and 
sailors, who are habituated to view objects at a distance, are 
long-sighted. 

Observation. In the management of children, whether in 
the nursery or school-room, it is very important that their 
books, or articles upon which they may labor, should be held 
at an appropriate distance from the eye. Were this attended 
to by the parent or instructor, we should not see so many 
persons with defective vision. 

940. Cleanliness, as well as the health of the eye, require 
that it be bathed every morning with pure water, either cold 
or tepid, accompanied with as little rubbing or friction as 
possible. In all instances, the secretion from the lachrymal 
glands, that sometimes collects at the angle of the eye, should 
be removed, as it contains saline matter. 

941. When small particles, or dust, get upon the eye, they 
produce much inconvenience, which is often increased by 

938. "What is the effect of repeatedly rising the eye in one direction ? 
939. Why are artisans and scholars generally short-sighted ? Why are 
sailors and hunters long-sighted ? How can defective vision in a great 
degree be prevented ? 940. "What reasons are there for bathing the eye ? 
941. How can dust and other small particles be removed from the eye ? 



HYGIENE OF THE ORGANS OF VISION. 413 

harsh attempts to remove them. The individual should be 
placed before a strong light, the lids held open with one 
hand, or by another person, and the particles removed with 
the corner of a fine linen or silk handkerchief. 

942. Sometimes the substance is concealed under the 
upper eyelid, and it may then be exposed by turning back 
the lid in the following manner : Take a knitting-needle, or 
small, slender piece of stick, which is perfectly smooth, and 
place it over the upper lid, in contact with, and just under 
the edge of the orbit ; then, holding it firmly, seize the eye- 
lashes with the fingers of the disengaged hand, and gently 
turn the lid back over the stick or needle. The inner side 
of the lid can then be examined, and any substance removed 
that may have been there concealed. Too many trials ought 
not to be made, if unsuccessful, as much inflammation may 
be induced ; but a surgeon should be consulted as soon as 
possible. 

Observation. Eyestones ought never to be placed in the 
eye, as they often cause more pain and irritation than the evil 
which they are intended to remedy. 

942. How removed from the upper eyelid ? "Why should not eyestones 
be used? 

35* 



414 ANATOMY, PHYSIOLOGY, AND HYGIENE. 



CHAPTER XLVI. 

THE SENSE OF HEARING. 

943. The sense of hearing is next in importance to that 
of vision. Through this sense we are enabled to perceive 
sounds, that not only subserve to our comfort and pleasure, 
but are instrumental in promoting our intellectual enjoyments. 
The organ of hearing, or the ear, is one of the most compli- 
cated in the human body. 

ANATOMY OF THE ORGANS OF HEARING. 

944. The ear is composed of three parts : 1st. The Ex- 
ternal Ear. 2d. The Tym'pan-um, or middle ear. 3d. The 
La'by-rinth, or internal ear. 

945. The external ear is composed of two parts : The 
Pin'na, (pavilion of the ear,) and the Me-a'tus Aud-it-o'ri-us 
Ex-ter'nus, (auditory canal.) 

946. The pinna is a cartilaginous plate which surrounds 
the entrance of the auditory canal. It presents many ridges 
and furrows, arising from the folds of the cartilage that 
form it. 

Observation. The pinna, in many animals, is movable ; 
in those that pursue their prey, it is generally directed for- 
ward ; in timid animals, as the hare and rabbit, it is directed 

943. What is said of the importance of hearing ? Is the ear complicated 
in its structure ? 944 — 982. Give the anatomy of the organs of hearing. 
944. Of how many parts is the ear composed ? Name them. 94-5. Give the 
parts of the external ear. 946. Describe the pinna. What is said in refer- 
ence to the pinna of many animals ? 



ANATOMY OF THE ORGANS OF HEARING. 415 

backward. In man, this part is but slightly under the control 
of the will. 

947. The meatus auditorius is a canal partly cartilagi- 
nous, and partly bony, about an inch in length, which extends 
inward from the pinna to the Mem'bra-na Tym'pan-i, (drum of 
the ear.) It is narrower in the middle than at the extremities. 
It is lined by an extremely thin pouch of cuticle, which, when 
withdrawn, after maceration, preserves the form of the canal. 
Some stiff, short hairs are also found in the interior of the 
channel, which stretch across the tube, and prevent the ingress 
of insects. Beneath the cuticle are a number of small folli- 



Fig. 144. 



4> 



Fig. 144. A representation of the four bones of the ear. The smallest is highly 
magnified. This bone is early matured, and in the adult it becomes united with the 
incus. These bones are retained in their places and moved by three ligaments and four 
muscles. 

948. The membrana tympani is a thin, semi-transparent 
membrane, of an oval shape. It is about three eighths of an 
inch in diameter, and is inserted into a groove around the 
circumference of the meatus, near its termination. This 
membrane is placed obliquely across the area of that tube. 
It is concave toward the meatus, and convex toward the 
tympanum. 

949. The tympanum consists of an irregular bony cavity, 
situated within the temporal bone. It is bounded externally 
by the membrana tympani ; internally by its inner wall ; and 
in its circumference by the petrous portion of the temporal 

947. "What is the meatus auditorius ? "What is found in this canal ? What 
is their use ? Where is the wax of the ear secreted. 948. Describe the 
membrana tympani. 949. "Where is the tympanum situated ? 



416 



ANATOMY, PHYSIOLOGY, AND HYGIENE. 



bone and mastoid cells. The tympanum contains four small 
bones, called the os-sic'u-la au-di'ta. These are named sepa- 
rately, the mal'le-us, in'cus, sta'pes, and or-bidu-lar. 

950. There are ten openings in the middle ear ; five large 
and five small. The larger openings are, the Me-a'tus Aud- 
it-o'ri-us Ex-ter'nus, Fe-nes'tra O-va'lis, (oval window,) Fe- 
nestra Ro-tun'da, (round window,) Mas'toid Cells, and 
Eu-sta' chi-an Tube. 

Fig. 145. 




Fig. 145. A representation of the pinna, meatus, membrana tympani, bones of the 
ear, and semicircular canals, a, The pinna, c, The meatus auditorius externus. 
g, The membrana tympani. k, The tympanum, e, The bones of the ear. b, The 
semicircular canals. /, The cochlea, h, The vestibule, i, The Eustachian tube. 
d, The auditory nerve. 

951. The fenestra ovalis is the opening of communica- 
tion between the tympanum and the vestibule. It is closed 
by the foot of the stapes, or bone of the ear, and by the lining 
membrane of both cavities. 

952. The fenestra rotunda serves to establish a com- 



"What does this cavity contain ? 950. How many openings in the tym- 
panum ? Explain fig. 145. 951. Describe the fenestra ovalis. 952. The 
fenestra rotunda. 



ANATOMY OF THE ORGANS OF HEARING. 



417 



munication between the tympanum and the cochlea. It is 
closed by a proper membrane, as well as by the lining of both 
cavities. 

953. The mastoid cells are very numerous, and occupy 
the whole of the interior of the mastoid process of the tem- 
poral bone, and part of the petrous bone. They communicate, 
by a large, irregular opening, with the upper and posterior 
circumference of the tympanum. 

Fig. 146. 




Fig. 146. A view of the labyrinth laid open. This figure is highly magnified. 
1, 1, The cochlea. 2, 3, Two channels, that wind two and a half turns around a 
central point, (5.) 7, The central portion of the labyrinth, (vestibule.) 8, The fora- 
men rotundum. 9, The fenestra ovalis. 11, 12, 13, 14, 15, 16, 17, 18, The semicircu- 
lar canals. The cochlea and semicircular canals open into the vestibule. 

954. The eustachian tube is a canal of communication, 
extending obliquely between the pharynx and the anterior 
circumference of the tympanum. In structure it is partly 



953. Where are the mastoid cells ? Explain fig. 146. 954. Describe the 
Eustachian tube. 



418 ANATOMY, PHYSIOLOGY, AND HYGIENE. 

fibro-cartilaginous and partly bony. It is broad and expanded 
at its pharyngeal extremity, and narrow and compressed at 
the tympanum. 

955. The small openings of the middle ear are for the 
entrance and exit of the chorda tympani, (a small nerve that 
crosses the drum of the ear,) and for the exit of the muscles 
that act upon the membrana tympani and bones of the ear. 

956. The labyrinth consists of a membranous and a bony 
portion. The bony labyrinth presents a . series of cavities 
which are channelled through the substance of the petrous 
bone. It is situated between the cavity of the tympanum and 
the Aud'it-o-ry Nerve. The labyrinth is divided into the 
Ves'ti-bule, Sem-i-cir 'cu-lar Canals, and Coch'le-a. 

957. The vestibule is a small, three-cornered cavity, 
situated immediately within the inner wall of the tympanum. 

958. The semicircular canals are three bony passages 
which communicate with the vestibule, into which two of them 
open at both extremities, and the third at one extremity. 

959. The cochlea forms the anterior portion of the laby- 
rinth. It consists of a bony and gradually tapering canal, 
about one and a half inches in length, which makes two turns 
and a half, spirally, around a central axis, called the mo-di'o-lus. 
The modiolus is large near its base, where it corresponds 
with the first turn of the cochlea, and diminishes in diameter 
toward its extremity. 

960. The interior of the canal of the cochlea is partially 
divided into two passages, by means of a bony and membra- 
nous plate. At the extremity of the modiolus, the two pas- 
sages communicate with each other. At the other extremity, 
one opens into the vestibule ; the other into the tympanum, by 

955. What passes through the small openings of the middle ear? 
956. Of what does the labyrinth consist ? Give the parts of the internal 
ear. 957. Describe the vestibule. 958. What is said of the semicircular 
canals ? 959. Why is the cochlea so called ? Of what does it consist ? 
960. How is the interior of the canal of the cochlea divided ? Where do 
they communicate with each other ? 



ANATOMY OF THE ORGANS OF HEARING. 419 

the foramen rotundum. The internal surface of the bony- 
labyrinth is lined by a fibro-serous membrane. 

961. The membranous labyrinth is smaller in size, but a 
perfect counterpart, with respect to form, of the bony vestibule, 
cochlea, and semicircular canals. Within this labyrinth are 
two small, elongated sacs, which are filled with a fluid. 

Fig. 147. 




i 

Fig. 147. A view of the auditory nerve. 1, The spinal cord. 2, The medulla 
oblongata. 3, The lower part of the brain. 4, The auditory nerve. 5, A branch to 
the semicircular canals. 6, A branch to the cochlea. 

962. The auditory nerve enters the temporal bone upon 
its internal surface, and divides into two branches, at the bot- 
tom of the cavity of the internal ear. These branches enter 
the structure of the elongated sacs and membranous labyrinth, 
radiating in all directions, and finally, they terminate upon 
the inner surface of the membrane, in minute papillae, resem- 
bling those of the retina. 

By what is the internal labyrinth lined ? 961. Describe the membranous 
labyrinth. What does fig. 147 represent ? 962. Where does the auditory 
nerve enter and divide ? Where do the branches of the auditory nerve 
enter and terminate ? 



420 ANATOMY, PHYSIOLOGY, AND HYGIENE. 



CHAPTER XLVII. 

PHYSIOLOGY OF THE ORGANS OF HEARING. 

963. Hearing is that function by which we obtain a knowl- 
edge of the vibratory motions of bodies, which constitute sounds. 
The precise function of all the different parts of the ear is not 
known. 

964. The function of that part of the external ear which 
projects from the head is to collect sounds and reflect them 
into the meatus. 

965. The membrana tympani serves to facilitate the trans- 
mission of sounds, and also to moderate their intensity. It is 
so arranged that it can be relaxed or tightened. 

Observation. This membrane, when healthy, has no open- 
ing ; and it must be apparent that the apprehension which is 
often expressed, that insects will penetrate further, is ground- 
less. The pain is owing to the extreme sensibility of the 
membrana tympani. 

966. The supposed office of the tympanum is to transmit 
the vibrations made on the drum to the internal ear. This is 
effected by the air which it contains, and by the chain of small 
bones that are enclosed in this cavity. 

967. The use of the Eustachian tube is to admit air into 
me tympanum, which renders the pressure on both sides equal, 
and thus its membrane is kept in a proper state of tension. 

963 — 971. Give the physiology of the organs of hearing. 963. What is 
hearing ? Are the precise functions of the different parts of the ear known ? 
964. What is the function of the external ear ? 965. Of the membrana 
tympani ? What observation in reference to this membrane ? 966. What is 
the supposed office of the middle ear ? 967. What is the use of the Eu- 
stachian tube ? 



PHYSIOLOGY OF THE ORGANS OF HEARING. 



421 



Observation. When near a cannon, or a field-piece, about 
being discharged, by opening the mouth the impression upon 
the auditory nerve will be diminished, and the unpleasant sen- 
sation lessened. This is the result of the air in the middle ear 
escaping through the Eustuchian tube, when the vibrations of 
the membrana tympani are violent. 

Fisr. 148. 




Fig. 148. A view of all the parts of the ear. 1, The tube that leads to the internal 
ear. 2, The drum of the ear. 3, 4, 5, The bones of the ear. 7, The central part 
of the labyrinth, (vestibule.) 8, 9, 10, The semicircular canals. 11, 12, The chan- 
nels of the cochlea. 13, The auditory nerve. 14, The channel from the middle ear 
to the throat, (Eustachian tube.) 

968. But little is known of the functions of the internal 
ear ; its parts are filled with a watery fluid, in which the fila- 
ments of the auditory nerve terminate. 



"What observation in this connection ? 
internal ear ? 

36 



968. What is the function of the 



422 ANATOMY, PHYSIOLOGY, AND HYGIENE. 

969. Many of the parts just enumerated aid in hearing, but 
are not absolutely essential to this sense. But if the vestibule 
and auditory nerve are diseased or destroyed, no sound is then 
perceived. If this sense is destroyed in early life, the person 
also loses the power of articulating words. Hence a man 
born deaf is always dumb. 

970. The transmission of sound through the different parts 
of the ear will now be explained by aid of fig. 148. The 
vibrations of air are collected by the external ear, and con- 
ducted through the tube (1) to the drum of the ear, (2.) From 
the drum the vibrations pass along the chain of bones, 
(3, 4, 5.) The bone 5 communicates with the internal ear, 
(7, 8, 9, 10, 11, 11, 11, 12, 12, 12.) From the internal ear 
the impression is transmitted to the brain by the nerve, (13.) 

971. The auditory nerve, like the optic, has but one func- 
tion, that of special sensibility. The nerves which furnish 
the ear with ordinary sensibility, proceed from the fifth pair. 



HYGIENE OF THE ORGANS OF HEARING. 

972. Hearing, like the other senses, is capable of very 
great improvement. By cultivation, the blind are enabled to 
judge with great accuracy the distance of bodies in motion, 
and even the height of buildings. It is also capable of im- 
provement when all the other senses are perfect. Thus the 
Indian will distinguish sounds that are inaudible to the white 



969. What parts of the ear are essential in order to hear sounds ? 
"What follows loss of hearing? 971. What is the office of the auditory 
nerve ? What nerves convey ordinary sensibility to the ear ? 972— 
978. Give the hygiene of the organs of hearing. 972. Is this sense capable 
of improvement ? How does this sense aid the blind ? Is it also capable 
of improvement when all the other senses are perfect ? In whom is this 
illustrated ? 

Note. Let the anatomy and physiology of the organs of hearing be 
reviewed, from fig. 148, or from anatomical outline plate No. 10. 



HYGIENE OF THE ORGANS OF HEARING. 423 

973. Acute hearing requires perfection in the structure and 
functions of the different parts of the ear, and that portion of 
the brain from which the auditory nerve proceeds. Deafness 
is by no means unfrequent. We will now advert to some of 
the common causes of imperfect hearing. 

974. The structure or functional action of the brain may 
be deranged by inflammation, by compression, or by debility, 
and produce deafness. The first is seen during inflammatory 
affections of the brain, and in fevers; the second is seen in 
accidental injuries of the head ; the third is seen in old age, 
and after severe diseases of the head, and fevers. In these 
cases, applications to, and operations upon, the ear do no good. 
The only remedy is to remove, if possible, the diseased con- 
dition of the brain. 

975. Imperfect hearing may be produced by the destruction 
of the membrana tympani, or removal of the bones of the 
ear, or the parts within the labyrinth. In these instances, 
medical treatment is of no avail, as the destroyed parts can- 
not be restored. 

976. Hearing may be rendered defective by a diminution 
of the vibratory character of the drum of the ear. This may 
result from a thickening of this membrane, or from an ac- 
cumulation of wax upon its outer surface. The increased 
thickness is usually the result of inflammation, either acute 
or chronic. The proper treatment is such as is efficient to 
remove inflammatory action. 

Observations. 1st. The introduction of heads of pins into 
the ear is a frequent cause of chronic inflammation of the 
membrana tympani. Hence this practice should never be 
adopted, and if acquired, should be abandoned. 

973. On what does acute hearing depend ? 974. State effects on the 
hearing in some conditions of the brain. How relieved ? 975. Of the 
effect on hearing when the bones of the ear or the labyrinth are destroyed ? 
Is medical treatment of any avail ? 976. What conditions of the drum of 
the ear may impair hearing ? How relieved ? What is said of the intro- 
duction of pins to cleanse the ear ? 



424 ANATOMY, PHYSIOLOGY, AND HYGIENE. 

2d. The accumulations of viscid wax may be softened by 
dropping some animal oil into the ear, and then removing it by 
ejecting warm soap suds a few hours subsequent to the use of 
the oil. This may be repeated for several successive days. 

977. Hearing may be impaired by obstruction of the Eu- 
stachian tube. The closure of this canal diminishes the vibra- 
tory character of the air within the tympanum, in the same 
manner as closing the opening in the side of a drum. For 
the same reason, enlarged tonsils, inflammation and ulceration 
of the fauces and nasal passages during and subsequent to an 
attack of scarlet fever, and the inflammation attending the 
" sore throat " in colds, are common causes of this obstruc- 
tion. 

978. The treatment of such cases of defective hearing, is 
to have the tonsils, if enlarged, removed by a surgeon ; for 
the inflammation and thickening of the parts remedial means 
should be applied, directed by a skilful physician. The nos- 
trums for the cure of deafness are generally of an oleaginous 
character, and may be beneficial in cases of defective hearing 
caused by an accumulation of wax upon the drum of the ear, 
but in this respect they are no better than the ordinary animal 
oils. 

"What is the remedy where there is an. accumulation of wax ? 977. What 
is the effect on hearing if the Eustachian tube is obstructed ? 978. What 
is the treatment when deafness is caused by inflammation or ulceration of 
the fauces ? What is said of the nostrums used for deafness ? 



MEANS OF PRESERVING THE HEALTH. 425 



CHAPTER XLVIII. 

MEANS OF PRESERVING THE HEALTH.* 

979. Our bodies are constituted in harmony with certain 
laws, and every person should learn these, in order to regu- 
late his actions and the performance of his duties, so that 
health may be unimpaired, and the power of enjoyment, 
activity, and usefulness continue while life lasts. 

980. It is a law of the bones and the muscles, that they 
should either be used in some vocation, or called into action 
by some social play and active sport. 

981. All admit that food is necessary to sustain life ; and 
unless it be of a proper quality, taken in proper quantities, and 
at proper times, the functions of the digestive organs will be 
deranged, and disease produced. 

982. Pure air is essential to the full enjoyment of health. 
The impure air of unventilated rooms may be breathed, and 
the effect be so gradual as not to arrest attention ; yet it is 
a violation of the physical laws, and, sooner or later, we pay 
the penalty in disease and suffering. 

983. The body also requires sleep ; and if it is not taken 
at the right time, or with regularity, we do not feel full refresh- 



* It is advised, that a thorough, review of the hygiene of the pre- 
ceding chapters be given from the suggestions contained in this. 

979 Why is it incumbent on every person to learn the laws of health ? 
980. Give a law of the muscles. 981. In preserving the health, is it neces- 
sary to give attention to the food which is eaten ? "Why ? 982. What 
beside food is essential to the full enjoyment of health ? What is said of 
the impure air of unventilated rooms ? 983. What should be observed in 
regard to sleep ? 

36* 



426 ANATOMY, PHYSIOLOGY, AND HYGIENE. 

ment from " tired nature's sweet restorer." Let youth be 
taught that " early to bed and early to rise " gives him health 
and its attendant blessings. The brain, like other organs of 
the body, should be called into action at proper times. 

984. From the extent of the surface of the skin, and the 
close sympathy that exists between it and those organs whose 
office is, to remove the waste particles of matter from the 
body, it therefore becomes very important in the preservation 
of the health, that the functions of this membrane be properly 
maintained. 

985. The function of the circulatory and secretory organs, 
together with the operations of absorption and nutrition, should 
be steadily maintained, as vitality and the generation of ani- 
mal heat are intimately connected with these processes. In 
the proper performance of these functions, very much depends 
on the observance of the laws of the muscular, digestive, 
respiratory, dermoid, and nervous apparatuses. 

REMOVAL OF DISEASE. 

986. It is seldom that a physician is called in the first 
stages of disease. At this important period, the treatment 
adopted should be proper and judicious, or the sufferings of 
the patient are increased, and life, to a greater or less degree, 
is jeopardized. Hence the utility of knowing what should be 
done, and what should not be done, in order that the health 
may be rapidly regained. 

987. In all instances of acute disease, it is proper to rest, 
not only the body, but the mind. To effect this, the patient 
should cease from physical exertion, and also withdraw his 



984. Why should the functions of the skin be properly maintained ? 
985. Show the necessity of maintaining properly other functions of the 
system. 986. What is important in the first stages of disease ? 987. What 
is proper in all instances of acute disease ? How can it be effected ? 



REMOVAL OF DISEASE. 427 

thoughts from study and business operations. This should be 
done, even if the person is but slightly indisposed. 

988. Select a room for a sick person that is exposed to as 
little external noise as possible, as impressions made on the 
organ of hearing greatly influence the nervous system. Like- 
wise select a spacious, well-ventilated apartment, that has no 
superfluous furniture. The practice of placing a sick person 
in a small, ill-arranged sleeping-room, when a more spacious 
room can be used, is poor economy, not to say unkind. 

989. Care is necessary in regulating the light of a sick- 
room. While a strong light would produce an increased 
action of the vessels of the brain, a moderate light would be 
an appropriate stimulus to this organ. It is seldom or never 
necessary to exclude all light from the sick-chamber. 

990. A sick person, whether a child or an adult, should not 
be disturbed by visitors, even if their calls are short. The 
excitement of meeting them is followed by a depression of the 
nervous system. The more dangerous and apparently nearer 
death the sick person is, the more rigorous should be the 
observance of this suggestion. Nor should the sick-room be 
opened to privileged classes ; for the excitement caused by a 
visit from relations and the virtuous, will do as much injury to 
the sick, as that produced by strangers and the vicious. 

991. The custom of visiting and conversing with sick friends 
during the intervals of daily labor, and particularly on Sunday, 
is a great evil. No person will thus intrude herself in the sick- 
chamber who cares more for the welfare of the suffering friend 
than for the gratification of a sympathetic curiosity. Inquiries 
can be made of the family respecting the sick, and compli- 
mentary or necessary messages can be communicated through 
the nurse. 



988. What rooms should be selected for the sick ? Why ? 989. What 
is said in reference to the quantity of light admitted into a cick-room ? 
990. What effect have calls on the sick ? 991. What is said of the custom 
of calling and conversing with the sick during the intervals of daily labor ? 



428 ANATOMY, PHYSIOLOGY, AND HYGIENE. 

Illustration. While attending a Miss B., of N. H., sick of 
fever, I pronounced her better, withdrew medicine, directed a 
simple, low diet, and the exclusion of all visitors. In the 
evening I was sent for to attend her. There was a violent 
relapse into the disease, which continued to increase in sever- 
ity until the fourth day, when death terminated her sufferings. 
I learned that, soon after I gave directions that no visitors 
be admitted into her room, several particular friends were per- 
mitted to enter the chamber and talk with the sick girl. Their 
conversation produced a severe headache ; and, to use the 
language of the patient, " it seemed as if their talk would 
kill me ; " and it did kill her. 

992. No solid food should be taken in the first stages of 
disease, even if the affection is slight. The thirst can be 
allayed by drinking cold water, barley-water, and other prep- 
arations of an unstimulating character. It is wrong to tempt 
the appetite of a person who is indisposed. The cessation 
of a desire for food, is the warning of nature, that the system 
is in such a state that it cannot be digested. 

993. When a patient is recovering from illness, the food 
should be simple, and in quantities not so great as to oppress 
the stomach. It should also be given with regularity. " Eat 
little and often," with no regard to regularity, is a pernicious 
practice. 

994. When a physician attends a sick person, he should 
have the special management of the food, particularly after 
the medicine has been withdrawn and the patient is convales- 
cent. The prevailing idea that every person may safely advise 
relative to food, or that the appetite of the convalescing per- 



Give an illustration. 992. "What suggestion relative to food in the first 
stages of disease ? How can the thirst be allayed ? 993. When the 
patient is convalescent, how should the food be given ? What is said of 
the practice of eating "little and often"? 994. Who should have the 
special management of food when medicine is withdrawn ? What idea 
prevails in the community ? 



EEX0VAL OF DISEASE. 429 

son is a competent guide, is dangerous, and cannot be too 
much censured. 

Illustration. In 1832, I attended a Miss M.. sick of fever. 
After an illness of a few days, the fever abated, and I direct- 
ed a simple, unstimulating diet. Business called me from 
the town two days. During my absence, a sympathizing, 
officious matron called ; found her weak, but improving ; and 
told her she needed food to strengthen her ; and that " it 
would now do her good." Accordingly, eggs and a piece of 
beefsteak were prepared, and given to the convalescent girl. 
She ate heartily, and the result was a relapse into a fever 
more violent than the first attack. 

995. It is very important in disease that the skin he kept 
clean. A free action of the vessels of this part of the body 
exerts a great influence in removing disease from the internal 
organs, as well as keeping them in health. If the twenty or 
thirty ounces of waste, hurtful matter, that passes through the 
" pores " of the skin in twenty-four hours, are not removed by 
frequent bathing and dry rubbing, it deranges the action of 
the vessels that separate this waste matter from the blood, and 
thus increases the disease of the internal organs. 

Illustration. Mrs. M. E., of X., Mass., was afflicted with 
disease of the lungs and cough. This was accompanied with 
a dry, inactive condition of the skin. As medicine had no 
salutary effect in relieving her cough, she was induced by the 
advice of the clergyman of the parish to enter upon a system- 
atic course of bathing twice every day. Soon the skin became 
soft, its proper functions were restored, the disease of the 
lungs yielded, and the cough disappeared. 

996. Even* sick person should breathe pure air. The 
purer the blood that courses through the body, the greater the 

Give an illustration of the evil effects attending such an idea. 995. Does 
the skin exert a great influence in removing disease from the internal 
organs, as well as in keeping them in health ? Give an illustration. 
996. Why should every sick person, particularly, breathe pure air? 



430 ANATOMY, PHYSIOLOGY, AND HYGIENE. 

energy of the system to remove disease. The confined, 
vitiated air of the sick-chamber, not unfrequently prolongs dis- 
ease ; and in many instances, the affection is not only aggra- 
vated, but even rendered fatal, by its injurious influences. 

Illustrations. 1st. In 1833, I was called, in consultation 
with another physician, to Mr. H., who was much debilitated, 
and delirious. For several successive days he had not slept. 
His room was kept very warm and close, for fear he would 
" take cold." The only change that I made in the treatment, 
was to open the door and window, at a distance from the bed. 
In a short time, the delirium ceased, and he fell into a quiet 
slumber. From this time he rapidly recovered, and the de- 
lirium was probably the result of breathing impure air. 

2d. Formerly, every precaution was used to prevent per- 
sons sick of the small-pox from breathing fresh air. When 
Mrs. Ramsay had this disease in Charleston, S. C, her friends, 
supposing that life was extinct, caused her body to be removed 
from the house to an open shed. The pure air revived the 
vital spark. The result probably would have been different, had 
she been kept a few hours longer in the vitiated air. 

997. The influence of habit should not be disregarded in 
the removal of disease. If food or drink is to be administered, 
however small in quantity or simple its quality, it should be 
given at or about the time when the ordinary meals were 
taken in health. 

998. Again, the usual time when the patient was in the 
habit of retiring for sleep should be observed, and all prepa- 
ration necessary for the sick-room during the night should be 
made previous to this hour. Efforts should also be made to 
evacuate the waste matter of the digestive and urinary organs 
at the period which habit has formed in health. This is not 

Are not diseases prolonged, and even rendered fatal, from breathing the 
impure, vitiated air of the sick-chamber ? Give illustration 1st. Give 
illustration 2d. 997. "What is said respecting the influence of habit in 
removing disease ? 



REMOVAL OF DISEASE. 431 

only a remedial agent in disease, but often precludes the 
necessity of laxative or drastic cathartics. 

999. Medicine is sometimes necessary to assist the natu- 
ral powers of the system to remove disease ; but it is only 
an assistant. While emetics are occasionally useful in remov- 
ing food and other articles from the stomach that would cause 
disease if suffered to remain, and cathartics are valuable, in 
some instances, to relieve the alimentary canal of irritating 
residuum, yet the frequent administration of either will cause 
serious disease. 

1000. Although medicine is useful in some instances, yet, 
in a great proportion of the cases of disease, including fevers 
and inflammations of all kinds, attention to the laws of health 
will tend to relieve the system from disease, more certainly 
and speedily, and with less danger, than when medicines are 
administered. 

1001. Thomas Jefferson, in writing to Dr. Wistar, of Phil- 
adelphia, said, " I would have the physician learn the limit 
of his art." I would say, Have the matrons, and those who 
are continually advising " herb teas," and other " cure-alls," 
for any complaint, labelled with some popular name, learn 
the limits of their duty, namely, attention to the laws of 
health. The rule of every family, and each individual, should 
be, to touch not, taste not of medicine of any kind, except 
when directed by a well-educated and honest physician, (sud- 
den disease from accidents excepted.) 

999. "What is said of the use of medicine ? 1000. Of its use in fevers 
and many other cases of disease ? 1001. What remark by Thomas Jeffer- 
son to Dr. "Wistar ? What should matrons learn ? What should be the 
rule of every person in regard to taking medicine ? What exception ? 



432 ANATOMY, PHYSIOLOGY, AND HYGIENE. 



CHAPTER XLIX. 

DIRECTIONS FOR NURSES. 

1002. The nurse requires knowledge and practice to 
enable her to discharge aright her duty to the patient, as 
much as the physician and surgeon do to perform what is 
incumbent on them. Woman, from her constitution and 
habits, is the natural nurse of the sick ; and, in general, no 
small portion of her time is spent in ministering at the 
couch of disease and suffering. 

1003. As the young and vigorous, as well as the aged and 
the infirm, are liable to be laid upon the bed of sickness, by an 
epidemic, or imprudent exposure, or by some accident, it is 
therefore necessary that the girl, as well as the matron, may 
know how she can render services in an efficient and proper 
manner. No girl should consider her education complete 
who is not acquainted with the principles of the duties of a 
general nurse and a temporary watcher. 

1004. It is to be regretted, that while we have medical 
schools and colleges to educate physicians, there is no institu- 
tion to educate nurses in their equally responsible station. In 
the absence of such institutions, the defect can be remedied, 
to some extent, by teaching every girl hygiene, or the laws of 
health. To make such knowledge more available and com- 
plete, attention is invited to the following suggestions relative 
to the practical duties of a nurse. 

1002. Does the nurse require knowledge and practice in her employment, 
as well as the physician ? Who is the natural nurse of the sick ? 
1003. What, then, is incumbent on every girl ? 1004. Should there be 
schools to educate nurses, as well as physicians and surgeons ? 



DIRECTIONS FOR NURSES. 433 

1005. Bathing. The nurse, before commencing to bathe 
the patient, should provide herself with water, two towels, a 
sponge, a piece of soft flannel, and a sheet. The temperature 
of the room should also be observed. 

1006. When the patient is feeble, use tepid or warm 
water. Cold water should only be used when the system has 
vigor enough to produce reaction upon the skin. This is 
shown by the increased redness of the skin, and a feeling of 
warmth and comfort, after a proper amount of friction. 
Before using the sponge to bathe, a sheet, or fold of cloth, 
should be spread smoothly over the bed, and under the patient, 
to prevent the bed-linen on which the patient lies from becom- 
ing damp or wet. 

1007. Apply the wet sponge to one part of the body at a 
time ; as the arm, for instance. By doing so, the liability of 
contracting chills is diminished. Take a dry, soft towel, wipe 
the bathed part, and follow this by vigorous rubbing with a 
crash towel, or, what, is better, a mitten made of this material ; 
then use briskly a piece of soft flannel, to remove all moisture 
that may exist on the skin, and particularly between the fingers 
and the flections of the joints. In this manner bathe the entire 
body. 

1008. The sick should be thoroughly bathed, at least twice 
in twenty-four hours. Particular attention should be given 
to the parts between the fingers and toes, and about the 
flections of the joints, as the accumulation of the excretions is 
most abundant on these parts. In bathing, these portions of 
the system are very generally neglected. The best time for 
bathing, is when the patient feels most vigorous, and freest 
from exhaustion. The practice of daubing the face and 
hands with a towel dipped in hot rum, camphor, and vinegar, 

1005. What should a. nurse provide herself with, before bathing a patient ? 
1006. "When should cold water be used ? 1007. How should the bathing 
then be performed, so that the patient may not contract a cold ? 1008. How 
often should a sick person be bathed ? "What is said of daubing the face 
and hands merely with a wet cloth r 

37 



434 ANATOMY, PHYSIOLOGY, AND HYGIENE. 

does not remove the impurities, but causes the skin soon to 
feel dry, hard, and uncomfortable. 

1009. Food. It is the duty of every woman to know how 
to make the simple preparations adapted to a low diet, in the 
most wholesome and the most palatable way. Water-gruel,* 
which is the simplest of all preparations, is frequently so ill- 
made as to cause the patient to loathe it. Always prepare the 
food for the sick, in the neatest and most careful manner. 

1010. When the physician enjoins abstinence from food, 
the nurse should strictly obey the injunction. She should be 
as particular to know the physician's directions about diet, as 
in knowing how and when to give the prescribed medicines, 
and obey them as implicitly. 

1011. When a patient is convalescent, the desire for food 
is generally strong, and it often requires firmness and patience, 
together with great care, on the part of the nurse, that the 
food is prepared suitably, and given at proper times. The 
physician should direct how frequently it should be taken. 

1012. Pure Air. It is the duty of the nurse to see that 
not only the room is well ventilated in the morning, but that 
fresh air is constantly admitted during the day. Great care 
must be taken, however, that the patient does not feel the 
current. 

1013. Bed-linen, as well as that of the body, should be aired 
every day, and oftener changed in sickness than in health. 
All clothing, when changed, should be well dried, and warmed 
by a fire previous to its being put on the patient or the bed. 



* Directions for making the simple preparations for the sick are 
found in almost every cook-book. 

1009. Should every woman know how to make the simple preparations 
adapted to a low diet ? 1010. Should the nurse strictly obey the injunc- 
tions of the physician relative to food? 1011. What period of a person's 
illness requires the most care in regard to the food ? 1012. Give another 
duty of the nurse. 1013. "What directions respecting the bed-linen of the 
patient ? What is necessary when there is a change of clothing ? 



DIRECTIONS FOR NURSES. 435 

1014. Temperature. The warmth of the chamber should 
be carefully watched by the nurse. The feelings of the 
patient or nurse are not to be relied on as an index of the 
temperature of the room. There should be a well-adjusted 
thermometer in every sick-room. This should be frequently 
consulted by the nurse. 

1015. The temperature of the sick-chamber should be 
moderate. If it is so cold as to cause a chill, the disease will 
be aggravated. If, on the other hand, it is too warm, the 
patient is enfeebled and rendered more susceptible to cold on 
leaving the sick-chamber. The Latin maxim, " In medio 
tutissimus ibis" (in medium there is most safety,) should be 
regarded in the rooms of the sick. 

1016. Quiet. The room of the patient should be kept free 
from noise. The community should be guided by this rule, 
that no more persons remain in the room of the sick, than the 
welfare of the patient demands. It is the duty of the physi- 
cian to direct when visitors can be admitted or excluded from 
the sick-room, and the nurse should see that these directions 
are enforced. 

1017. The movements of the attendants should be gentle and 
noiseless. Shutting doors violently, creaking hinges, and all 
unnecessary noise, should be avoided. Most persons refrain 
from loud talking in the sick chamber, but are not equally 
careful to abstain from whisjiering, which is often more trying 
than a common tone. 

1018. It is the duty of the nurse to ascertain the habits 
of the patient as respects the period for eating and sleep, 
when in health, that she may prepare the food and arrange 
the sick-room in accordance with the practice of the patient. 



1014. Why should there be a well-adjusted thermometer in every sick- 
chamber ? 1015. What is said of the temperature of the sick-chamber ? 
1016. Why should the sick-room be kept quiet ? 1017. What is said of 
noise in the sick-chamber? Of whispering ? 1018. Should the habits of 
the patient be regarded in reference to the period for eating and sleep ? 



436 ANATOMY, PHYSIOLOGY, AND HYGIENE. 

If the person who is sick is ignorant of the necessity of the 
removal of the waste products from the system, the nurse 
should invite attention to these functions at such periods as 
are in accordance with the previous habits of the patient. 

1019. The deportment and remarks of the nurse to the 
patient should be tranquil and encouraging. The illness of a 
friend, or persons who have recently died, should not be alluded 
to in the sick-room. No doubts or fears of the patient's 
recovery, either by a look or by a word, should be communi- 
cated by the nurse in the chamber of the sick. When such 
information is necessary to be communicated, it is the duty of 
the physician to impart it to the sick person. 

1020. The nurse should not confine herself to the sick- 
room more than six hours at a time. She should eat her food 
regularly, sleep at regular periods, and take exercise daily in 
the open air. To do this, let her quietly leave the room when 
the patient is sleeping. A watcher, or temporary nurse, may 
supply her place. There is but little danger of contracting 
disease, if the nurse attends to the simple laws of health, and 
remains not more than six hours at a time in the sick-room. 



DIRECTIONS FOR WATCHERS. 

1021. These necessary assistants, like the nurse, should 
have knowledge and practice. They should ever be cheerful, 
kind, firm, and attentive in the presence of the patient. 

1022. A simple, nutritious supper should be eaten before 
entering the sick-room; and it is well, during the night, to 
take some plain food. 

lOra. "What should be the deportment of the nurse toward the patient ? 
Should doubts and fears of the patient's recovery be communicated in the 
sick-room ? "When necessary to impart such intelligence, on whom does it 
depend ? 1020. How long should a nurse remain in the sick-chamber at a 
time ? 1021. "What qualifications are necessary in a watcher ? 1022. What 
directions in regard to the food of the watcher ? 



DIRECTIONS FOR WATCHERS. 437 

1023. When watching in cold weather, a person should be 
warmly dressed, and furnished with an extra garment, as a 
cloak or shawl, because the system becomes exhausted toward 
morning, and less heat is generated in the body. 

1024. Light-colored clothing should be worn by those who 
have care of the sick, in preference to dark-colored apparel ; 
particularly if the disease is of a contagious character. Ex- 
periments have shown, that black and other dark colors will 
absorb more readily the subtile effluvia that emanate from 
sick persons, than white or light colors. 

1025. Whatever may be wanted during the night, should 
be brought into the sick-chamber, or the adjoining room, be- 
fore the family retires for sleep, in order that the slumbers of 
the patient be not disturbed by haste, or searching for needed 
articles. 

1026. The same general directions should be observed by 
watchers, as are given to the nurse ; nor should the watcher 
deem it necessary to make herself acceptable to the patient 
by exhausting conversation. 

1027. It can hardly be expected that the farmer, who has 
been laboring hard in the field, or the mechanic, who has 
toiled during the day, is qualified to render all those little 
attentions that a sick person requires. Hence, would it not 
be more benevolent and economical to employ and pay watch- 
ers, who are qualified by knowledge and training, to perform 
this duty in a faithful manner, while the kindness and sympa- 
thy of friends may be practically manifested by assisting to 
defray the expenses of these qualified and useful assistants? 

1023. "When watching in cold -weather, what precaution is necessary ? 
1024. What is said relative to the color of the clothing worn in the 
sick-room ? 1025. What suggestions to watchers relative to the arrange- 
ment of the sick-chamber ? 1023. What should watchers observe ? 
1027. What is said of employing those persons to watch who labor hard 
during the day ? 

37* 



APPENDIX 



POISONS AND THEIR ANTIDOTES. 

1028. Poisoning, either from accident or design, is of such frequency 
and danger, that it is of the greatest importance that every person should 
know the proper mode of procedure in such cases, in order to render imme- 
diate assistance when within his power. 

1029. Poisons are divided into two classes — mineral (which include the 
acids) and vegetable. 

1030. The first thing, usually, to he done, when it is ascertained that a 
poison has been swallowed, is to evacuate the stomach, unless vomiting 
takes place spontaneously. Emetics of the sulphate of zinc, (white vitriol,) 
or ipecacuanha, (ipecac,) or the wine of antimony, should be given. 

1031. "When vomiting has commenced, it should be aided by large and 
frequent draughts of the following drinks : flaxseed tea, gum-water, slip- 
pery-elm tea, barley water, sugar and water, Or any thing of a mucilaginous 
or diluent character. 

MINERAL POISONS. 

1032. Ammonia. — The water of ammonia, if taken in an over-dose, and 
in an undiluted state, acts as a violent corrosive poison. 

1033. The best and most effectual antidote is vinegar. It should be 
administered in water, without delay. It neutralizes the ammonia, and 
renders it inactive. Emetics should not be given. 

1034. Antimony. — The wine of antimony and tartar emetic, if taken in 
over-doses, cause distressing vomiting. In addition to the diluent, muci- 
laginous drinks, give a tea-spoonful of the sirup of poppies, paregoric, or 

1028. Is it Useful to know the antidotes or remedies for poison ? 1029. Into how 
many classes are poisons divided ? 1030. What is the first thing to he done when it is 
ascertained that poison has been swallowed? 1031. What should be taken after 
the vomiting has commenced? 1032. What effect has an over-dose of ammonia? 
1033. The antidote ? Should an emetic be given for this poison ? 1034. What effect 
has an over-dose of the wine of antimony or tartar emetic? 



APPENDIX. 439 

twenty drops of laudanum, every twenty minutes, until five or six doses 
have been taken, or the vomiting ceases. 

1035. The antidotes are nutgalls and oak bark, which may be adminis- 
tered in infusion, or by steeping in water. 

1036. Arsenic. — When this has been taken, administer an emetic of 
ipecac, speedily, in mucilaginous teas, and use the stomach-pump as soon 
as possible. 

1037. The antidote is the hydrated peroxide of iron. It should be kept 
constantly on hand at the apothecaries' shops. It may be given in any 
quantity, without injurious results. 

1038. Copper. — The most common cause of poisoning from this metal, 
is through the careless use of cooking utensils made of it, on which the 
acetate of copper (verdigris) has been allowed to form. When this has been 
taken, immediately induce vomiting, give mucilaginous drinks, or the 
white of eggs, diffused in water. 

1039. The antidote is the carbonate of soda, which should be administered 
without delay. 

1040. Lead. — The acetate (sugar) of lead is the preparation of this metal, 
which is liable to be taken accidentally, in poisonous doses. Induce imme- 
diate vomiting, by emetics and diluent drinks. 

1041. The antidote is diluted sulphuric acid. When this acid is not to 
be obtained, either the sulphate of magnesia, (epsom salts,) or the sulphate 
of soda, (glauber's salts,) will answer every purpose. 

1042. Mercury. — The preparation of this mineral by which poisoning 
is commonly produced, is corrosive sublimate. The mode of treatment to 
be pursued when this poison has been swallowed, is as follows : The ichites 
of a dozen eggs should be beaten in two quarts of cold water, and a tumbler- 
full given every two minutes, to induce vomiting. When the whites of 
eggs are not to be obtained, soap and water should be mixed with wheat 
flour, and given in copious draughts, and the stomach-pump introduced as 
soon as possible. Emetics or irritating substances should not be given. 

1043. Nitre — Saltpetre. — This, in over-doses, produces violent poison- 
ous symptoms. Vomiting should be immediately induced by large doses 



1035. What is the antidote ? 1036. What should immediately be done when arsenic 
is swallowed ? 1037. What is the antidote? Can any quantity of this preparation of 
iron be given without injurious results ? 103S. What should be given when verdigris 
has been taken into the stomach ? 1039. What is the antidote? 1040. What, should 
immediately be given when sugar of lead is taken? 1041. What is the antidote ? 
1042. Give the treatment when corrosive sublimate has been swallowed. 1043. What 
effect has an over-dose of saltpetre ? What treatment should be adopted ? 



440 APPENDIX. 

of mucilaginous, diluent drinks ; but emetics which irritate the stomach, 
should not be given. 

1044. Zinc. — Poisoning is sometimes caused by the sulphate of zinc, 
(white vitriol.) When this takes place, vomiting should be induced, and 
aided by large draughts of mucilaginous and diluent drinks. Use the 
stomach-pump as soon as possible. 

1045. The antidote is the carbonate, or super-carbonate of soda. 

1046. Nitric, (aqua fortis,) muriatic, (marine acid,) or stjxphuric 
(oil of vitriol,) acids, may be taken by accident, and produce poisonous 
effects. 

1047. The antidote is calcined magnesia, which should be freely admin- 
istered, to neutralize the acid and induce vomiting. When magnesia can- 
not be obtained, the carbonate of potash (salaeratus) may be given. Chalk, 
powdered and given in solution, or strong soap suds, will answer a good 
purpose, when the other articles are not at hand. It is of very great im- 
portance that something be given speedily, to neutralize the acid. One of 
the substances before mentioned should be taken freely, in diluent and 
mucilaginous drinks, as gum-water, milk, flaxseed, or slippery-elm tea. 
Emetics ought to be avoided. 

1048. Oxalic Acid. — This acid resembles the sulphate of magnesia, 
(epsom salts,) which renders it liable to be taken, by mistake, in poisonous 
doses. Many accidents have occurred from this circumstance. They can 
easily be distinguished by tasting a small quantity. Epsom salts, when 
applied to the tongue, have a very bitter taste, while oxalic acid is in- 
tensely sour. 

1049. The antidote is magnesia, between which and the acid a chemical 
action takes place, producing the oxalate of magnesia, which is inert. 
When magnesia is not at hand, chalk, lime, or carbonate of potash, (salaera- 
tus,) will answer as a substitute. Give the antidote in some of the muci- 
laginous drinks before mentioned. No time should be lost in introducing 
the stomach-pump as soon as a surgeon can be obtained. 

1050. Ley. — The ley obtained by the leaching of ashes maybe taken 
by a child accidentally. The antidote is vinegar, or oil of any kind. The 
vinegar neutralizes the alkali by uniting with ft, forming the acetate of 
potash. The oil unites with the alkali, and forms soap, which is less caus- 
tic than the ley. Give, at the same time, large draughts of mucilaginous 
drinks, as flaxseed tea, &c. 

1044. What is the antidote for white vitriol ? 1047. What is the antidote for aqua 
fortis and oil of vitriol? Should emetics he avoided? 1048. How can oxalic acid he 
distinguished from epsom salts ? 1049. What is the antidote for an over-dose of ox- 
alic acid? When magnesia cannot be obtained, what will answer as a substitute? 
1050. What is the antidote when ley is swallowed ? 






APPENDIX. 441 



VEGETABLE POISONS. 

1051. The vegetable poisons are quite as numerous, and many of them 
equally as virulent, as any in the mineral kingdom. We shall describe the 
most common, and which, therefore, are most liable to be taken. 

1052. Opium. — This is the article most frequently resorted to by those 
wishing to commit suicide, and, being used as a common medicine, is easily 
obtained. From this cause, also, mistakes are very liable to be made, and 
accidents result from it. Two of its preparations, laudanum and paregoric, 
are frequently mistaken for each other ; the former being given when the 
latter is intended. 

1053. Morphia, in solution, or 'morphine, as it is more commonly called 
by the public, is a preparation of the drug under consideration, with which 
many cases of poisoning are produced. It is the active narcotic principle 
of the opium ; and one grain is equal to sis of this drug in its usual form. 

1054. When an over-dose of opium, or any of its preparations, has been 
swallowed, the stomach should be evacuated as speedily as possible. To 
effect this, as much tartar emetic as can be held on a ten cent piece, or as 
much ipecacuanha as can be held on a twenty-five cent piece, should be 
dissolved in a tumbler of warm water, and one half given at once, and the 
remainder in twenty minutes, if the first has not, in the mean time, oper- 
ated. In the interval, copious draughts of warm water, or warm sugar 
and water, should be drank. 

1055. The use of the stomach-pump, in these cases, is of the greatest 
importance, and should be resorted to without delay. After most of the 
poison has been evacuated from the stomach, a strong infusion of coffee 
ought to be given ; or some one of the vegetable acids, such as vinegar, 
or lemon-juice, should be administered. 

1056. The patient should be kept in motion, and salutary effects will 
often be produced by dashing a bucket of cold water on the head. Arti- 
ficial respiration ought to be established, and kept up for some time. If 
the extremities are cold, apply warmth and friction to them. After the 
poison has been evacuated from the stomach, stimulants, as warm wine and 
water, or warm brandy and water, should be given, to keep up and sustain 
vital action. 

1057. Stramonium — Thorn-Apple. — This is one of the most active 
narcotic poisons, and, when taken in over-doses, has, in numerous in- 
stances, caused death. 

1051. Are vegetable poisons as numerous and as virulent in their effects as mineral? 
1052. What is said of opium and its preparations ? 1054, 1055, 105G. What treatment 
Bhould be adopted when an over-dose of opium or any of its preparations is taken? 
1057. What is said of stramonium? ^ 



442 APPENDIX. 

1058. Hyosciamus — Henbane. — This article, which is used as a medi- 
cine, if taken in improper doses, acts as a virulent irritating and nar- 
cotic poison. 

1059. The treatment for the two above-mentioned articles is similar to 
that of poisoning from over-doses of opium. 

1060. Conium — Hemlock. — Hemlock, improperly called, by many, cicuta, 
when taken in an over-dose, acts as a narcotic poison. It was by this 
narcotic that the Athenians used to destroy the lives of individuals con- 
demned to death by their laws. Socrates is said to have been put to death 
by this poison. When swallowed in over-doses, the treatment is similar 
to that of opium, stramonium, and henbane, when over-doses are taken. 

1061. Belladonna — Deadly Nightshade. — Camphor. Aconite — 
Monkshood, Wolfsbane. Bryonia — Bryony. Digitalis — Foxglove. 
Dulcamara — Bittersweet. Gamboge. Lobelia — Indian Tobacco. 
Sanguinaria — Bloodroot. Oil of Savin. Spigelia — Pinkroot. 
Strychnine — Nux vomica. Tobacco. — All of these, when taken in 
over-doses, are poisons of greater or less activity. The treatment of 
poisoning, by the use of any of these articles, is similar to that pursued 
in over-doses of opium. (See Opium, page 441.) 

1062. In all cases of poisoning, call a physician as soon as possible. 

1058. Of henbane? 1059. What should be the treatment when an over-dose of 
stramonium or henbane is taken ? 1060. What name is sometimes improperly given to 
conium, or hemlock? How was this narcotic poison used by the Athenians? How are 
the effects of an over-dose counteracted ? 1061. What is the treatment when an over- 
dose of deadly nightshade, monkshood, foxglove, bittersweet, gamboge, lobelia, bloodroot, 
tobacco, &.C., is taken? 1062. Should a physician be called in all cases when poison 
is swallowed ? 



GLOSSARY 



Ab-duc'tor [L. abduco, to lead away.] 
A muscle which moves certain p;irts, 
by separating them from the axis of the 
body. 

Ab-do'men. [L. abdo, to hide.] That 
part of the body which lies between 
the thorax and the bottom of the 
pelvis. 

Ab-dom'in-is. Pertaining to the ab- 
domen. 

A-ce-tab'u-lum. [L. acetum, vinegar.] 
The socket for the head of the thigh- 
bone ; an ancient vessel for holding 
vinegar. 

A-CE'XIC. [L. acetum, vinegar.] Relat- 
ing to acetic acid. This is always com- 
posed of oxygen, hydrogen, and carbon, 
in the same proportion. 

A-chil/lis. A term applied to the ten- 
don of two large muscles of the leg. 

A-CRO'MI-ON. [Gr. axpos,akros, highest, 
and ojp'is, omos, shoulder.] A process 
of the scapula that joins to the clavicle. 

Ad-duc'tor. [L. adduce-, to lead to.] 
A muscle which draws one part of the 
body toward another. 

Al-BU-gin'e-A. [L. albus, white.] A 
term applied to white textures. 

Al-bu'men. [L. albus, white.] An ani- 
mal substance of the same nature as the 
white of an egg. 

A-lu'min-um. [L.] The name given 
to the metallic base of alumina. 

Al/VE-O-EAR. [L. alveolus, a socket.] 
Pertaining to the sockets of the teeth. 

Am-mo'ni-a. An alkali. It is composed 
of three equivalents of hydrogen and 
one of nitrogen. 

A-na.s'to-MOSE. [Gr. ava, ana, through, 



and amna, stoma, mouth.] The com- 
munication of arteries and veins with 
each other. 
An-a-tom'i-cal. Relating to the part3 
of the body, when dissected or sep- 
arated. 
A-nat'o-my. [Greek ava, ana, through, 
and ropri, tome, a cutting.] The de- 
scription of the structure of animals. 
The word anatomy properly signifies 
dissection. 

An'gu-li. [L. angulus, a corner.] A 
term applied to certain muscles on ac- 
count of their form. 

An-i-MAL'cu-LjE. [L. animalcula, a 
little animal.] Animals that are only 
perceptible by means of a microscope. 

An'nu-lar. [L. annulus, a ring.] Hav- 
ing the form of a ring. 

An-ti'cus. [L.] A term applied to cer- 
tain muscles. 

A-ort'a. [Gr. aoorri, aorte ; from avp, 
aer, air, and r^pera, tereo, to keep.] 
The great artery that arises from the 
left ventricle of the heart. 

Ap-o-neu-RO'sis. [Gr. airo, apo, from, 
and vevpov, neuron, a nerve.] The 
membranous expansions of muscles 
and tendons. The ancients called 
every white tendon neuron, a nerve. 

Ap-pa-ra'tus. [L. ajrparo, to prepare.] 
An assemblage of organs designed to 
produce certain results. 

Ap-peivd'ix. [L., an addition.] Some- 
thing appended or added. 

A'que-ous. [L. aqua, water.] Par- 
taking of the nature of water. 

A-RACII'NOID. [Gr. apa\vr], arachne, a 
spider, and e <5<k, eidos, form.] Re- 



444 



GLOSSARY. 



sembling a spider's web. A thin mem- 
brane that covers the brain. 

AR'BOR. [L.] A tree. Arbor vitx. The 
tree of life. A term applied to a part 
of the cerebellum. 

Ar'TE-RY. [Gr. anp, acr, air, and rnosui, 
tereo, to keep ; because the ancients 
thought that the arteries contained only 
air.] A tube through which blood 
flows from the heart. 

A-RYT-e'noid. [Gr. apvraiva,arutaina, 
a ewer, and ados, cidos, form.] The 
name of a cartilage of the larynx. 

As-cend'ens. [L.J Ascending; ris- 
ing. 

As-phyx'i-a. [Gr. a, a, not, and o-0u£j?, 
sphyxis, pulse.] Originally, want of 
pulse ; now used for suspended respira- 
tion, or apparent death. 

As-trag'a-lus. [Gr.] The name of 
a bone of the foot. One of the tarsal 
bones. 

Aud-i'tion. [h. audio, to hear.] Hear- 
ing. 

Aud-it-o'ri-us. [L.] Pertaining to the 
organ of hearing. 

Au'RI-CLE. [L. auricula, the external 
ear j from auris, the ear.] A cavity of 
the heart. 

Au-Ric'u-LAR. [L. auricula.] Pertain- 
ing to the auricle. 

Ax-il'la. [L.] The armpit. 

Ax'il-la-RY. Belonging or relating to 
the armpit. 

A-zote'. [Gr. a, a, not, and £gj>/, zoe, 
life.] Nitrogen. One of the constit- 
uent elements of the atmosphere. So 
named because it will not sustain life. 

Ben-ZO'IC. Benzoic acid. A peculiar 

vegetable acid, obtained from benzoin 

and some other balsams. 
Bi'ceps. [L. bis, twice, and caput, a 

head.] A name applied to muscles with 

two heads at one extremity. 
Bi-cus'pids. [L. bis and cuspis, a point.] 

Teeth that have two points upon their 

crown. 
Bile. [L. bilis.] A yellow, viscid fluid 

secreted by the liver. 



Bl-PEN'NI-FORM. [L. bis and penna, a 
feather.] Bipenniform muscle. Having 
fibres on each side of a common 
tendon. 

Brach'i-AL. [L. brachium.] Belonging 
to the arm. 

BRE'vis. [L.] Brevis, short; brevior, 
shorter. 

Bronch'i-a, -Mm [L.] A division of 
the trachea that passes to the lungs. 

Bronch'i-al. Relating to the bronchia. 

Bronch-i'tis. [L.] Aii inflammation 
of the bronchia. 

Btjc-ci-na'tor. [L. buccmum, a trum- 
pet.] The name of a muscle of the 
cheek, so named because used in blow- 
ing wind instruments. 

Bur'sjE Mu-CO'SA. [L. bursa, a purse, 
and mucosa, viscous.] Small sacs, 
containing a viscid fluid, situated about 
the joints, under tendons. 

CjE'cum. [L.] Blind ; the name given 
to the commencement of the colon. 

Calx, Cal'cis. [L.] The heel-bone. 

Cal'ci-um. [L.] The metallic basis 
of lime. 

Cap'il-la-ry. [L. capillus, a hair.] 
Resembling a hair; small. 

Cap'su-lar. Pertaining to a capsule. 

Cap'sule. [L. capsula, a little chest.] 
A membranous bag, enclosing a part. 

Ca'put. [L.J The head. Caput coli. 
The head of the colon. 

Car'bon. [L. carbo, a coal.] Pure char- 
coal. An elementary combustible sub- 
stance. 

Car-bon'ic. Pertaining to carbon. 

Car'di-ac. [Gr. Ka/jSia, kardia, heart.] 
Relating to the heart, or upper orifice 
of the stomach. 

Car'ne-a, -M. [L. caro, carnis, flesh.] 
Fleshy. 

Ca-ROT'id. [Gr. Kapoi,karos, lethargy.] 
The great arteries of the neck that con- 
vey blood to the heart. The ancieius 
supposed drowsiness to be seated in 
these arteries. 

Car'pal. [L. carpus, the wrist.] Re- 
lating to the wrist. 



GLOSSARY. 



445 



Car'pus, -I. [L.J The wrist. 

C'AR'TI-LA»E. [L. cartilage] Gristle. 
A smooth, elastic substance, softer than 
bone. 

Car-ti-lag'in-ous. Pertaining to car- 
tilage. 

Cau-ca'sian. One of the races of 
men. 

C'A'VA. [L.] Hollow. Vena cava. A 
name given to the two great veins of 
the body. 

Cel/lu-lar. [L. cellula, a little cell.] 
Composed of cells. 

Cer-e-bel/lum. [L.] The hinder and 
lower part of the brain, or the little 
brain. 

Oer'e-bral. Pertaining to the brain. 

Cer'e-brum. [L.] The front and large 
part of the brain. The term is some- 
times applied to the whole contents of 
the cranium. 

Cer'e-bro-Spi'nae. Relating to the 
brain and spine. 

Cer'vix. [L.] The neck. 

Cer'vi-cal. Relating to the neck. 

Chest. [Sax.] The thorax ; the trunk 
of the body from the neck to the 
abdomen. 

Chlo'rine. [Gr. xXuon^chloros, green.] 
Chlorine gas, so named from its color. 

Chor'da,-& [L.] A cord. An assem- 
blage of fibres. 

Cho'roid. [Gr. x°P inv i chorion.] A 
term applied to several parts of the 
body that resemble the skin. 

Chile. [Gr. xvAoj, chulos, juice.] A 
nutritive fluid, of a whitish appearance, 
which is extracted from food by the 
action of the digestive organs. 

Chyl-I-FI-ca'TION. [chyle and L. facio, 
to make.] The process by which chyle 
is formed. 

Chyme. [Gr. x v A*°s> chumos, juice.] A 
kind of grayish pulp formed from the 
food in the stomach. 

Chym-i-fi-ca'tion. [chyme and L. 
facio, to make.] The process by which 
chyme is formed. 

Cie'ia-ry. [L. cilia, eyelashes.] Be- 
longing to the eyelids. 



Cin-e-ri'tious. [L. cinis, ashes.] Hav- 
ing the color of ashes. 

Clav'I-CLE. [L. clavicula, from clavis, a 
key.] The collar-bone ; so called from 
its resemblance in shape to an ancient 
key. 

Clei'do. A term applied to some mus- 
cles that are attached to the clavicle. 

Co-ag'u-lum. [L.] A coagulated mass, 
a clot of blood. 

Coc'cyx. [Gr.] An assemblage of 
bones joined to the sacrum. 

Coch'ee-a. [Gr. kox\oj, kochlo, to twist ; 
or L. cochlea, a screw.] A cavity of the 
ear resembling in form a snail shell. 

Co'lon. [Gr.] A portion of the large 
intestine. 

Co-lum/na, -JE. [L.] A column or 
pillar. 

Com-mtj'nis. [L ] A name applied to 
certain muscles. 

Com-plex'us. [L. complector, to em- 
brace.] The name of a muscle that 
embraces many attachments. 

Com-press'or. [L. con, together, and 
premo, pressus, to press.] A term ap- 
plied to some muscles, that compress 
the parts to which they are attached. 

Con'dyle. [Gr. kuvSvXos, kondulos, a 
knuckle, a protuberance.] A promi- 
nence on the end of a bone. 

Con-junc-ti'va. [L. con, together, and 
jungo, to join.] The membrane that 
covers the anterior part of the globe 
of the eye. 

Cop'per. A metal of a pale, red color, 
tinged with yellow. 

COR-A'COID. [Gr. Kopal, korax, a crow, 
and etSos, eidos, form.] A process 
of the scapula shaped like the beak 
of a crow. 

Co'Rl-ON. [Gr. x°P l0V > chorion, skin.] 
The true skin. 

Corn'e-a. [L. cornu, a horn.] The 
transparent membrane in the fore part 
of the eye. 

Cos'ta. [L. costa, a coast, side, or rib.] 
A rib. 

CRIB'RI-FORM. [L. cribrum, a sieve, and 
forma, form.] A plate of the ethmoid 



446 



GLOSSARY. 



bone, through which the olfactory nerve 
passes to the nose. 

Cri'coid. [Gr. KptKog, krikos, a ring, 
and etSos, eldos, form.] A name given 
to a cartilage of the larynx, from its form. 

CRYS'TAL-LINE. [L. crxjstallinus, con- 
sisting of crystal.] Crrjstalline lens. 
One of the humors of the eye. It is 
convex, white, firm, and transparent. 

Cu'bi-tus, -I. [L. cubitus, the elbow.] 
One of the bones of the forearm, also 
called the ulna. 

Cu'boid. [Gr. kv0os, kubos, a cube, and 
udos, eldos, form.] Having nearly the 
form of a cube. 

Cu-ne'i-form. [L. cuneus, a wedge.] 
The name of bones in the wrist and foot. 

Cus'pid. [L. cuspis, a point.] Having 
one point. 

Cu-ta'jve-ous. [L. cutis, skin.] Be- 
longing to the skin. 

Cu'ti-cle. [L. cutis.] The external 
layer of the skin. 

Cu'Tis Ve'ra. [L. cutis, and vera, true.] 
The internal layer of the skin ; the true 
skin 

Del'toid. [Gr. SeXra, delta, the Greek 

letter A, and urW, eldos, form.] The 

name of a muscle, that resembles in 

form the Greek letter A. 
Dens. [L.] A tooth. 
Dent'al. [L. dens, tooth.] Pertaining 

to the teeth. 
De-press'or. [L.] The name of a 

muscle that draws down the part to 

which it is attached. 
Derm'oid. [Gr. Stpfia, derma, the skin, 

and ciSos, eldos, form.] Resembling 

skin. 
Pe-scend'ens. [L. de and scando, to 

climb.] Descending, falling. 
Dl'A-PHRAGM. [Gr. Suuppayim, dia- 

phragma, a partition.] The midriff; a 

muscle separating the chest from the 

abdomen. 
Di-AR-RH(E'a. [Gr. St > ppsw, diarrlico, 

to flow through.] A morbidly frequent 

evacuation of the intestines. 
Dl-AS'TO-LE. [Gr. SiaortWo), diastello, 



to put asunder.] The dilatation of the 
heart and arteries when the blood 
enters them. 

Di-ges'tion. [L. digestio.] The pro- 
cess of dissolving food in the stomach, 
and preparing it for circulation and 
nourishment. 

Dig-I-to'rttm. [L. digitus, a finger.] 
A term applied to certain muscles of the 
extremities. 

Dor'sal. [L. dorsum, the back.] Per- 
taining to the back. 

Du-o-de'num. [L. duodenus, of twelve 
fingers' breadth.] The first portion of 
the small intestine. 

Du'RA Ma'ter. [L. durus, hard, and 
mater, mother.] The outermost mem- 
brane of the brain. 

Dys'en-ter-y. [Gr. Svs, dus, bad, and 
evrepta, enteria, intestines.] A dis- 
charge of blood and mucus from the 
intestines attended with tenesmus. 

Dys-pep'si-a. [Gr. Svs, dus, bad, and 
ninra>, pepto, to digest.] Indigestion, 
or difficulty of digestion. 

En-am'el. [Fr.] The smooth, hard 

substance which clovers the crown or 

visible part of a tooth. 
Ep-i-derm'is. [Gr. tin, epi, upon, and 

Sepfia, derma, the skin.] The scarf- 
skin ; the cuticle. 
Ep-i-glot'tis. [Gr. em, epi, upon, and 

y\(x)rra, glotta, the tongue.] Oue of 

the cartilages of the glottis. 
Eu-sta'chi-an Tube. A channel from 

the fauces to the middle ear, named 

from Eustachius, who first described it. 
Ex'cRE-MENT. [L. excerno, to separate.] 

Matter excreted and ejected ; alvine 

discharges. 
Ex-cre-men-ti'tial. Pertaining to 

excrement. 
Ex'cre-to-ry. A little duct or vessel, 

destined to receive secreted fluids, and 

to excrete or discharge them ; also, a 

secretory vessel. 
Ex-ha'lant. [L. exhalo, to send forth 

vapor.] Having the quality of exhaling 

or evaporating. 



GLOSSARY. 



447 



Ex-tens'OR. [L.] A name applied to 
a muscle that serves to extend any part 
of the body ; opposed to Flexor. 

Fa'cial. [L. fades, face.] Pertaining 
to the face. 

Falx. [L. falx, a scythe.] A process 
of the dura mater shaped like a 
scythe. 

Fas'ci-a. [L. fascia, a band.] A ten- 
dinous expansion or aponeurosis. 

Fas-cic'u-lus, -li. [L. fascis, a bundle.] 
A little bundle. 

Faux, -ces. [L.] The top of the throat. 

Fem'o-ral. Pertaining to the femur. 

Fem'o-ris. A term applied to muscles 
that are attached to the femur. 

Fe'mur. [L.] The thigh-bone. 

Fe-NES'tra, -U3I. [L. fenestra, a win- 
dow.] A term applied to some open- 
ings into the internal ear. 

Fi'bre. [L. fibra.] An organic fila- 
ment, or thread, which enters into the 
composition of every animal and vege- 
table texture. 

Fi'brin. A peculiar organic substance 
found in animals and vegetables ; it is 
a solid substance, tough, elastic, and 
composed of thready fibres. 

Fi'brous. Composed or consisting of 
fibres. 

Fi'bro-Car'ti-lage. An organic tis- 
sue, partaking of the nature of fibrous 
tissue and that of cartilage. 

Fib'u-la. [L., a clasp.] The outer and 
lesser bone of the leg. 

Fib'u-lar. Belonging to the fibula. 

FlL'A-MENT. [L. filamenta, threads.] 
A fine thread, of which flesh, nerves, 
skin, &c, are composed. 

Flec'tion. [L.fiectio.] The act of bend- 
ing. 

Fol'li-cle. [L. folliculus, a small 
bag.] A gland ; a little bag in animal 
bodies. 

Fore 'arm. The part of the upper 
extremity between the elbow and 
hand. 

Fos'sa. [L., a ditch.] A cavity in a 
bone, with a large aperture. 



FR^'NUM. [L., a bridle.] Franum lin- 
gua. The bridle of the tongue. 

Function. [L. fangor, to perform.] 
The action of an organ or system of 
organs. 

Fun'gi-form. [L. fungus and forma.] 
Having terminations like the head of a 
fungus, or a mushroom. 

Gan'gli-on, -a. [Gr.] An enlarge- 
ment in the course of a nerve. 

Gas'tRic. [Gr. yaarno, gaster, the 
stomach.] Belonging to the stomach. 

GAS-TROC-NE 'MI-US. [Gr. yaarr/p, gas- 
ter, the stomach, and Kvrijiri, kneme, the 
leg.] The name of large muscles of 
the leg. 

Gel'a-titv. [L. gelo, to congeal.] A 
concrete animal substance, transparent 
and soluble in water. 

GLE'NOID. [Gr. yXni-r/, glcne, a cavity.] 
A term applied to some articulate cav- 
ities of bones. 

Glos'sa. [Gr.] The tongue. Names 
compounded with this word are ap- 
plied to muscles of the tongue. 

Glos'so-Pha-ryn'gi-al Relating to 
the tongue and pharynx. 

Glot'tis. [Gr.] The narrow opening 
at the upper part of the larynx. 

Glu'te-us. [Gr.] A name given to 
muscles of the hip. 

Hem'OR-RHAGE. [Gr. aiua,haima, blood, 
and pnyvvto, regnuo, to burst.] A dis- 
charge of blood from an artery or vein. 

Hu'mer-us. [L.] The bone of the arm. 

Hy'a-loid. [Gr.] A transparent mem- 
brane of the eye. 

Hy'dro-gex. [Gr. vScjp, water, and 
yevvaco, to generate.] A gas which con- 
stitutes one of the elements of water. 

HY'GI-ENE. [Gr. vyietvov, hagiehwn, 
health.] The part of medicine which 
treats of the preservation of health. 

Hy'oid. [Gr. v and ei6og,eidos, shape.] 
A bone of the tongue resembling the 
Greek letter upsilon in shape. 

Hy-oid'e-us. Pertaining to the hyoid 
bone. 



443 



GLOSSARY. 



Hy'po-glos'sal. Under the tongue. 
The name of a nerve of the tongue. 

Il'e-um. [Gr. si Aw, eilo, to wind.] A 

portion of the small intestines. 
Il'i-ac [From the aliove.] The flank ; 

pertaining to the small intestine. 
Il/i-um. The haunch-bone. 
IN-CI'SOR. [L. incido, to cut] A front 

tooth that cuts or divides. 
In'dex. [L. indico, to show.] The fore- 
finger ; the pointing finger. 
In-nom-I-NA'ta. [L. in, not, and nomen, 

name.] Parts which have no proper 

name. 
In-os'cu-lAte. [L. in and osculatus, 

from osculor, to kiss.] To unite, as 

two vessels at their extremities. 
In'ter. [L.] Between. 
In-ter-cost'al. [L. inter, between, 

and casta, a rib.] Between the ribs. 
In-ter-no'di-i. [L. inter, between, and 

nodus, knot.] A term applied to some 

muscles of the forearm. 
In-ter-sti'tial. [L. inter, between, 

and sto, to stand.] Pertaining to or con- 
taining interstices. 
In-tes'tines. [L. intus, within.] The 

canal that extends from the stomach to 

the anus. 
I'RIS. [L., the rainbow.] The colored 

circle that surrounds the pupil of the 

eye. 
I'vo-RY. A hard, solid, fine-grained 

substance of a fine white color; the 

tusk of an elephant. 

Je-ju'num. [L., empty.] A portion of 

the small intestine. 
Ju'gu-lar. [L. jugulum, the neck.] 

Relating to the throat. The great veins 

of the neck. 

La'bi-tjm, La'bi-i. [L.J The lips. 

Lab'y-rinth. [Gr.] The internal 
ear, so named from its many wind- 
ings. 

Lach'ry-mal. [L. lachryma, a tear.] 
Pertaining to tears. 

Lac'te-al. [L., lac, milk.] A small 



vessel or tube of animal bodies for con- 
veying chyle from the intestine to the 
thoracic duct. 

Lam'i-na, -m. [L.] A plate, or thin 
coat lying over another. 

Lar'ynx. [Gr. A*pi>)|, larunz.] The 
upper part of the windpipe. 

Lar-yn-gi/tis. Inflammation of the 
larynx. 

La-tis'si-mus, -mi. [L., superlative of 
latus, broad.] A term applied to some 
muscles. 

Le-va'tor. [L. levo, to raise.] A name 
applied to a muscle that raises some 
part. 

Lig'a-ment. [L. ligo, to bind.] A 
strong, compact substance serving to 
bind one bone to another. 

Lin'e-a, -JE. [L.] A line. 

Lin'gua, -m. [L.] A tongue. 

Liv'er. The name of one of the ab- 
dominal organs, the largest gland in the 
system. It is situated below the 
diaphragm, and secretes the bile. 

Lobe. A round projecting part of an 
organ. 

Lon'gus, Lon'gi-or. [L., long, longer.] 
A term applied to several muscles. 

Lum'bar. [L. lumbus, the loins.] Per- 
taining to the loins. 

Lymph. [L. lympha, water.] A color- 
less fluid in animal bodies, and con- 
tained in vessels called lymphatics. 

Lym-phat'ic. A vessel of animal 
bodies that contains or conveys lymph. 

Mag-ne'si-um. The metallic base of 

magnesia. 
Mag'nus, -na, -num. [L m great.] A 

term applied to certain muscles. 
Ma'jor. [L., greater.] Greater in ex- 
tent or quantity. 
Man'ga-nese. A metal of a whitish 

gray color. 
Mar'row. [Sax.] A soft, oleaginous 

substance, contained in the cavities of 

bones. 
MAS-SE'TER. [Gr. iiatyaanjxaijTnassaomai^ 

to chew.] The name of a muscle of 

the face. 



GLOSSARY, 



449 



Mas'ti-cate, Mas-ti-ca'tion. [L. 
mastico.'] To chew ; the act of chew- 
ing. 

Mas'TOID. [Gr. ixavTos, mastos, breast, 
and ei6us, eldos, form.] The name of 
a process of the temporal bone behind 
the ear. 

Mas-toid'e-us. A name applied to 
muscles that are attached to the mas- 
toid process. 

Max-il'la. [L.] The jaw-bone. 

Max'il-la-RY. Pertaining to the jaw. 

Max'i-mus, -mi. [L., superlative of 
magims, great.] A term applied to sev- 
eral muscles. 

Me-a'tus. [L. mco, to go.] A passage 
or channel. 

Me-di-as'tine. A membrane that sep- 
arates the chest into two parts. 

Me'di-UM, -a. [L.] The space or sub- 
stance through which a body passes 
to any point. 

Med'ul-la-RY. [L., medulla, marrow.] 
Pertaining to marrow. 

Me-dul'la. Ob-lon-ga'ta. Com- 

mencement of the spinal cord. 

Me-dul'la Spi-jja'lis. The spinal 
cord. 

Mem'bra-na. A membrane; a thin, 
white, flexible skin formed by fibres 
interwoven like net-work. 

Mem/bra-nous. Relating to a mem- 
brane. 

Mes'en-ter-Y. [Gr. utrros, mesns, the 
middle, and evrtpov., enteron, the intes- 
tine.] The membrane in the middle 
of the intestines, by which they are 
attached to the spine. 

Mes-en-ter'ic. Pertaining to the mes- 
entery. 

Met-a-car'pal. Relating to the meta- 
carpus. 

)1et-a-car'pus. [Gr. fiera, meta, after, 
and tcapnos, karpos, wrist.] The part 
of the hand between the wrist and 
fingers. 

Met-a-tar'sal. Relating to the meta- 
tarsus. 

Met-a-tar'sus. [Gr. usra, meta, after, 
and Tapaos, tarsos, the tarsus.] The 

38* 



instep. A term applied to seven bones 

of the foot. 
Mid'riff. [Sax. mid, and hrife, the 

belly.] See Diaphragm. 
MlJT'l-ftLUS, -i. [L] The smallest. A 

term applied to several muscles. 
Mi'nor. [L.] Less, smaller. A term 

applied to several muscles. 
Mi'tral. [L. mitra, a mitre.] The 

name of the valves in the left side of 

the heart. 
Mo-di'o-lus. [L. modus, a measure.] 

A cone in the cochlea around which 

the membranes wind. 
Mo'lar. [L. viola, a mill.] The name 

of some of the large teeth. 
Mol'lis. [L.] Soft. 
Mo'tor, -es. [L. movee, to move.] A 

mover. A term applied to certain 

nerves. 
Mu'cous. Pertaining to mucus. 
Mu'cus. A viscid fluid secreted by the 

mucous membrane, which it serves to 

moisten and defend. 
Mus'cle. A bundle of fibres enclosed 

in a sheath. 
Mus'cu-LAR. Relating to a muscle. 
My-o'des. A term applied to certain 

muscles of the neck. 

Na'sal. Relating to the nose. 

Na'sus. [L.j the nose.] The nostrils. 

Nerve. An organ of sensation and mo- 
tion in animals. 

Nerv'ous. Relating to the nerves. 

Neu-ri-lem'a. [Gr. vevpov, neuron, a 
nerve, and \eufia, lema, a sheath.] 
The sheath or covering of a nerve. 

Ni'grum. [L.J Black. 

Ni'tro-gex. That element of the air 
which is called azote. 

Nu-tri'tion. The art or process of 
promoting the growth, or repairing the 
waste of the system. 

Oc-cip-i-ta'lis. Pertaining to the back 

part of the head. 
Oc'ci-put. [L. ob and caput, the head.] 

The hinder part of the head. 
Oc-u-lo'rum. Of the eyes. 



450 



GLOSSARY. 



Oc'u-LUS, -I. [L.] The eye. 

CE-soph'a-GTJS. [Gr. otcu, oio, to carry, 
and (payio, phago, to eat.] The name 
of the passage through which the food 
passes from the mouth to the stomach. 

O-lec'ra-non. [Gr. oi'kcve, olcne, the 
cubit, and KpOLvov, kranon, the head.] 
The elbow ; the head of the ulna. 

Ol-fact'o-ry. [L. oleo, to smell, and 
facto, to make.] Pertaining to smell- 
ing. 

O-men'tum. [L.] The caul. 

O'jio. [Gr. w^oi, Omos, the shoulder.] 
Names compounded of this word are 
applied to muscles attached to the 
shoulder. 

Oril-THAl/MIC. [Gr. oa)6a\pos, oph- 
thalmos, the eye.] Belonging to the eye. 

Op-po'nens. That which acts in oppo- 
sition to something. The name of two 
muscles of the hand. 

Op'ti-cus, Op'tic. [Gr. o-mfxai, op- 
tomai, to see.] Relating to the eye. 

Or-bic'c-lar. [L. orbis, a circle.] 
Circular. 

Or-bic-u-ea'ris. A name applied to 
several muscles. 

Or'gan. A part of the system destined 
to exercise some particular function. 

Or'i-gin. Commencement ; source. 

Os. [L.] A bone ; the mouth of any 
thing. 

O'RIS. [L. os, oris.] Of the mouth. 

Os Hy-oid'es. [Gr. See Hyoid.] 
The name of the bone at the base of 
the tongue. 

Os'ma-zome. [Gr. oo-pr), osme, smell, 
and £w//o?, zomos, broth.] A principle 
obtained from animal fibre which gives 
the peculiar taste to broth. 

Os'sa. [L., plural of os, bone.] Bones. 

Os'se-ous. Pertaining to bones. 

Os-si-fi-ca'tion. The formation of 
bones in animals. 

Os'si-fy. [L. ossa, bones, and facio, to 
make.] To convert into bone. 

Os'sis. Of a bone. 

O-va'le. [Li.] The shape of an egg. 

Ox-al'io. Pertaining to sorrel. Oxalic 
acid is the acid of sorrel. It is com- 



posed of two equivalents of carbon 
and three of oxygen. 
Ox'y-gen. A permanently elastic fluid, 
invisible and inodorous.* One of the 
components of atmospheric air. 

Pa-la'tum. [L.] The palate ; the roof 
of the mouth. 

Pal-pe-bra'rum. [L. palpebra, the 
eyelid.] Of the eyelids. 

Pax/mar. [L. palma, the palm.] Be- 
longing to the hand. 

Pal-ma'ris. A term applied to some 
muscles attached to the palm of the 
hand. 

Pan'cre-as. [Gr. -nav, pan, all, and 
Kpeas, kreas, flesh.] The name of one 
of the digestive organs. 

Pan-cre-at'ic. Belonging to the pan- 
creas. 

Pa-pie'la, -je. [L.] Small conical 
prominences. 

Pa-ral'y-sis. Abolition of function, 
whether of intellect, sensation, or mo- 
tion. 

PA-REN'CHY-MA. [Gr. itapeyxcu, pa- 
rengcheo, to pour through.] The sub- 
stance contained between the blood- 
vessels of an organ. 

Pa-ROt'id. [Gr. napa, para, near, and 
cjroi, otos, the gen. of ovj, ous, the 
ear.] The name of the largest salivary 
gland. 

Pa-tel'la, -m. [L.] The knee-pan. 

Pa-thet'i-cus,-ci. [Gr. n ad cj, pathos, 
passion.] The name of the fourth pair 
of nerves. 

Pec'tus. [L.J The chest. 

Pec'to-ral. Pertaining to the chest. 

Pec-to-ra'LIS. Belonging to the chest. 

Pe'dis. [L., gen. of pes, the foot.] Of 
the foot. 

Pel'i-tongs. A term applied to masses 
of fat. 

Pel'li-cee. [L., dim. of pellis, the 
skin.] A thin skin or film. 

Pel/vic. Relating to the pelvis. 

Pel'vis. [L.] The basin formed by 
the large bones at the lower part of the 
abdomen. 



GLOSSARY. 



451 



Pen'ni-form. [L. penna, a feather.] 
Having the form of a feather, or quill. 

Per-1-cak/di-UM. [Gr. neat, peri, around, 
and KapSia, kardia, the heart.] A mem- 
brane that encloses the heart. 

Per-i-chon'dri-um. [Gr. nspty peri, 
around, and xovSpos,chondros, cartilage.] 
A membrane that invests cartilage. 

Per-i-cra'ni-uik. [Gr. Kept, and Kpa- 
viov, kranion, the cranium.] A mem- 
brane that invests the skull. 

Per'ma-nent. Durable ; lasting. 

Per-i-stal/TIC. [Gr. n£pioT£\\(x),peri- 
stello, to involve.] A movement like 
the crawling of a worm. 

Per-spi-ra'tion. [li. per, through, and 
spiro, to breathe.] The excretion from 
the skin. 

PHAL'ANX, -GES. [Gr. <pa\ayl, phalanx, 
an army.] Three rows of small bones 
forming the fingers or toes. 

Pha-lan'gi-al. Belonging to the fin- 
gers or toes. 

Pha-ryn'ge-al. Relating to the pha- 
rynx. 

PllAR'YNX. [Gr. cpapvyt, pharunx.] The 
upper part of the oesophagus. ' 

Phos'phor-us. [Gr. <pcos, phos, the 
light, and (pcpco, phero, to bear.] A com- 
bustible substance, of a yellowish col- 
or, semi-transparent, resembling wax. 

Phren'ic. [Gr. fprjy, phren, the mind.] 
Belonging to the diaphragm. 

PlIYS-I-OL/O-GY. [Gr. (pvais, phusis, 
nature, and \nyos, logos, a discourse.] 
The science of the functions of the 
organs of animals and plants. 

Pi'a Ma'ter. [L., good mother.] The 
name of one of the membranes of the 
brain. 

Pig-men'tum. [L.] Paint; a prepa- 
ration of colors. 

Pin'na. [L., a wing.] A part of the ex- 
ternal ear. 

Pjla-tys'ma. [Gr. Tr\arvs,platus, broad.] 
A muscle of the neck. 

Pleu'ra, -JE. [Gr. nXevpa, pleura, the 
side.] A thin membrane that covers 
the inside of the thorax, and also forms 
the exterior coat of the lungs. 



Pletj'RAL. Relating to the pleura. 

Plex'us. [L. plecto, to weave together.] 
Any union of nerves, vessels, or fibres, 
in the form of net-work. 

Pneu-MO-GAS'TRIC. [Gr. nvevnov, pneu- 
mon, the lungs, and yaarrjp, gaster, the 
stomach.] Belonging to both the stom- 
ach and lungs. 

Pol/ei-cis. [L.] A term applied to 
muscles attached to the finders and toes. 

Pons. [L.] A bridge. Pons varolii. 
A part of the brain formed by the union 
of the crura cerebri and cerebelli. 

Pop-lit-e'al. [L. poples, the ham.] 
Pertaining to the ham or knee-joint. A 
name given to various parts. 

Pos'ti-cus. [L.] Behind ; posterior. 
A term applied to certain muscles. 

Por'ti-o Du'ra. [L., hard portion.] 
The facial nerve ; 8th pair. 

Por'ti-o Moi/lis. [L., soft portion.] 
The auditory nerve ; 7th pair. 

Po-tas'smjm. [L.] The metallic basis 
of pure potash. 

Pro-bos'cis. [Gr. npo, pro, before, and 
/?<>07ia>. bosko, to feed.] The snout or 
trunk of an elephant or other animal. 

Proc'ess. A prominence or projection. 

Pro-na'tor. [L. promts, turned down- 
ward.] The muscle of the forearm 
that moves the palm of the hand down- 
ward. 

Pso'as. [Gr. xpnat, psoai, the loins.] 
The name of two muscles of the leg. 

Pul-mon'ic, -\ 

Pul'aio-na-ry, C [L.pulmo, the lungs ] 

Pul-mo-na'lis. j 
Belonging or relating to the lungs. 

Pu'pil. A little aperture in the centre 
of the iris, through which the rays of 
light pass to the retina. 

Py-lor'ic. Pertaining to the pylorus. 

PY-LO'RUS. [Gr. T7v\copog, pulZros, a 
gate keeper.] The lower orifice of the 
stomach, with which the duodenum 
connects. 

Ra'di-us. [L., a ray, a spoke of a 
wheel.] The name of one of the 
bones of the forearm. 



452 



GLOSSARY. 



Ra-di-a'lis. Radial ; belonging to the 
radius. 

Ra'di-ate. Having lines or fibres that 
diverge from a point. 

Ra'mus. [L.] A branch. A term ap- 
plied to the projections of bones. 

Rec-re-men-ti'tial. [L. re, again, 
and cerno, to secrete.] Consisting of 
superfluous matter separated from that 
which is valuable. 

Rec'tum. The third and last portion of 
the intestines 

Rec'tus, -i. [L.J Straight ; erect. A 
term applied to several muscles. 

Re-sid'u-al. Pertaining to waste matter. 

Re-sid'u-um. [L.] Waste matter. The 
faeces. 

Res-pi-ra'tion. [L. re, again, and 
spiro, to breathe.] The act of breathing. 
Inspiring air into the lungs and expel- 
ling it again. 

Re-spi'ra-to-ry. Pertaining to respi- 
ration ; serving for respiration. 

Ret'i-na. [L., rete, a net.] The essen- 
tial organ of sight. One of the coats 
of the eye, formed by the expansion of 
the optic nerve. 

Ro-tun'dum,-a. [L.] Round; circular. 

Ru'GA, -JE. [L.] A wrinkle ; a fold. 

Sac'cu-LUS. [L., dim. of saccus, a bag.] 
A little sac. 

Sa'cral. Pertaining to the sacrum. 

Sa'crum. [L., sacred.] The bone which 
forms the posterior part of the pelvis, 
and is a continuation of the spinal 
column. 

Sa-li'va. [L.] The fluid which is 
secreted by the salivary glands, which 
moistens the food and mouth. 

Sal'i-va-ry. That which belongs to 
the saliva. 

San'GUIN-E-OUS. [L. sanguis, the blood.] 
Bloody ; abounding with blood ; ple- 
thoric. 

Sar-to'ri-us. [L. sartor, a tailor.] A 
term applied to a muscle of the thigh. 

Sca'ea, -jE. [L., aladder.] Cavities of 
the cochlea. 

Sca-Le'nus [Gr. (TKaXrjvoi, skalenos, 



unequal.] A term applied to some 
muscles of the neck. 

Scapii'oid. [Gr. onagri, skaphe, a little 
boat.] The name applied to one of the 
wrist-bones. 

Scap'u-LA. [L.] The shoulder-blade. 

Scap'u-lar. Relating to the scapula. 

Scarf-Skin. The outer, thin integu- 
ment of the body ; the cuticle. 

Sci-at'ic. [Gr., pertaining to the loins.] 
The name of the large nerve of thi 
loins and leg. 

Scle-rot'ic. [Gr. ax^r/pos, skleros, 
hard.] A membrane of the eye. 

Se-ba'ceous. [L., sebum, tallow.] Per- 
taining to fat; unctuous matter. 

Se-cre'tion. The act of secerning ; 
the act of producing from the blood 
substances different from the blood it- 
self, as bile, saliva. The matter se- 
creted, as mucus, bile, &c. 

Se-cre'to-RY. Performing the office 
of secretion. 

Se-cun'dus. Second. A term applied 
to certain muscles. 

Sem-i-cir'cu-lar. Having the form of 
a naff circle. The name of a part of 
the ear. 

Sem-i-ten-di-no'stjs. [L semi, half, 
and tendo, a tendon.] The name of 
a muscle. 

Sep'tum. [L.] A membrane that di- 
vides two cavities from each other. 

Se'rous. Thin; watery. Pertaining to 
serum. 

Se'rum. [L.] The thin, transparent 
part of blood. 

Ser-ra'tus. [L. serro, to saw.] A term 
applied to some muscles of the trunk. 

Sig'moid [Gr.] Resembling the Greek 
s, sigma. 

Si-li'ci-um. A term applied to one 
of the earths. 

Si'nus. [L., a bay.] A cavity, the in- 
terior of which is more expanded than 
the entrance. 

Skel'e-ton. [Gr. o-ksXXm, skello, to 
dry.] The aggregate of the hard parts 
of the body ; the bones. 

So'di-um. The metallic base of soda. 



GLOSSARY, 



453 



SPHINC'TER. [Gr. cfiyyo), sphing-o, to 
restrict.] A muscle that contracts or 
shuts an orifice. 

Spi'nal. Cord. A prolongation of the 
brain. 

Spi-na'eis. Relating to the spine. 

Spine. A thorn. The vertebral col- 
umn ; back-bone. 

Spi'nous. Belonging to the spinal col- 
umn. 

Spleen. The milt. It is situated in 
the abdomen, and attached to the 
stomach. 

Speen'ic. Relating to the spleen. 

Sple'ni-us. The name of a muscle of 
the neck. 

Sta'pes. The name of one of the 
small bones of the ear. 

Ster'num. The breast-bone. The bone 
that forms the front of the chest from 
the neck to the stomach. 

Stom'ach. The principal organ of the 
digestive apparatus. 

Stra'tum. [L. sterno, to stew.] A 
bed ; a layer. 

Sty'loid. [L. stylus, a pencil.] An 
epithet applied to processes that resem- 
ble a style, a pen. 

Sub-cla'vi-an. [li. sub, under, and cla- 
vis, a key.] Situated under the clavicle. 

Sub-li'mis. High in place. 

Sub-lin'gual. [L. sub, under, and 
lingua, the tongue.] Situated under 
the tongue. 

Sub-Max'il-la-ry. [L. sub, under, and 
maxilla, the jaw-bone.] Located un- 
der the jaw. 

Sul/phur. A simple, mineral substance, 
of a yellow color, brittle, insoluble in 
water, but fusible by heat. 

Su-pe-ri-o'ris. A term applied to cer- 
tain muscles. 

Su-pi-na'tor. [L.] A muscle that 
turns the palm of the hand upward. 

Sut'ure. [L. sw0, to sew.] The seam or 
joint that unites the bones of the skull. 

Syn-O'vi-a. [Gr. aw, sun, with, and 
uov, oon, an egg.] The fluid secreted 
into the cavities of joints for the pur- 
pose of lubricating them. 



Syn-O' vi-a:l. Pertaining to synovia. 

Sys'tem. An assemblage of organs, 
composed of the same tissues, and 
intended for the same functions. 

Sys-tem'ic. Belonging to the general 
system. * 

Sys'to-LE. [Gr. avaTcXXco, sustello, to 
contract.] The contraction of the heart 
and arteries for expelling the blood and 
carrying on the circulation. 

Tar'sal. Relating to the tarsus. 

Tar'sus. [L.] The posterior part of the 
foot. 

Ten'don. [Gr. teivo). teino, to stretch.] 
A hard, insensible cord, or bundle of 
fibres, by which a muscle is attached 
to a bone. 

Ten'di-na, -JE. Pertaining to a tendon. 

Tens'or. A muscle that extends a 
part. 

Ten-tac'u-la, -m. [L. tcnto, to seize.] 
A filiform process or organ on the bodies 
of various animals. 

Ten-to'ri-um. [L. Undo, to stretch.] 
A process of the dura mater which lies 
between the cerebrum and cerebellum. 

Te'res. [L. teres, round.] An epithet 
given to many organs, the fibres of 
which are collected in small bundles. 

Tho'rax. [Gr.] That part of the skel- 
eton that composes the bones of the 
chest. The cavity of the chest. 

Tho-rac'ic. Relating to the chest. 

Thy'roid. [Gr. dvpeos, thureos, a 
shield.] Resembling a shield. A carti- 
lage of the larynx. 

Tib'i-a. [L., a flute.] The large bone 
of the leg. 

Tib-i-a'eis, Tib'i-al. Relating to the 
tibia. 

Tis'sue. The texture or organization 
of parts. 

Ton'sil. [L.] A glandular body in the 
throat or fauces. 

Tra'ciie-a. [Gr. Tpaxvs , trachus, rough.] 
The windpipe. 

Tra'che-al. Belonging to the trachea. 

Trans- verse',Trans-ver-sa'lis. Ly- 
ing in a cross direction. 



454 



GLOSSARY. 



Tra-pe'zi-tjs. The name of a muscle, 
so called from its form. 

Tkj/ceps. [L. tres, three, and caput, 
head.] Three. A name given to mus- 
cles that have three attachments at one 
extremity. 

Tri-cus'pid. [L. tres, three, and cuspis, 
point.] The triangular valve3 in the 
right side of the heart. 

Troch'le-a. [Gr. rpo;y;a\(rt, trochalia, 
a pulley.] A pulley-like cartilage, over 
which the tendon of a muscle of the 
eye passes. 

Troch-le-a'ris. The name of a mus- 
cle of the eye. 

Trunk. The principal part of the body, 
to which the limbs are articulated. 

Tu'BER-CLE. [L. tuber, a bunch.] A 
small push, swelling, or tumor, on ani- 
mal bodies. 

Tu-ber-os'i-ty. The state of being 
knobbed or protuberant. 

Tvm'pan-um. [L.] The middle ear. 

Ul/NA. [L.] A bone of the forearm. 
Ul'nar, Ul-na'ris. Relating to the 

ulna. 
U'ric. [Gr. ovpov, ouron, urine.] An 

acid contained in urine, and in gouty 

concretions. 
U-ve'a. [L. uva, a grape.] Resembling 

grapes. A thin membrane of the eye. 
U'vu-LA. A soft body, suspended from 

the palate, near the aperture of the 

nostrils, over the glottis. 

Vac'cine Vi'rtjs. [L. vacca, a cow, 
virus, poison.] Pertaining to cows ; 
derived from cows. 

Valve. Any membrane, or doubling 
of any membrane, which prevents fluids 
from flowing back in the vessels and 
canals of the animal body. 

Vae'vu-la, -JE. A valve. 



Vas'cu-lar. [L. vasculum, a vessel.] 

Pertaining to vessels ; abounding in 

vessels. 
Vas'tus. [L.] Great, vast. Applied 

to some large muscles. 
Veins. Vessels that convey blood to 

the heart. 
Ve'nous. Pertaining to veins. 
Ven'tri-cle. [L. venter, the stomach.] 

A small cavity of the animal body. 
Ven tric'u-lar. Relating to ventri- 
cles. 
Ver-mic'u-EAR. [L. vermiculus, a little 

worm.] Resembling the motions of a 

worm. 
Verm-i-form'is. [L. vermis, a worm, 

and forma, form.] Having the form 

and shape of a worm. 
Vert'e-bra, m. [L. verto, to turn.] 

A joint of the spinal column. 
Vert'e-bral. Pertaining to the joints 

of the spinal column. 
Ves'i-cle. [L. vesica, a bladder.] A 

little bladder, or a portion of the cuticle 

separated from the cutis vera and filled 

with serum. 
Ves'ti-bule. [L.] A porch of a house. 

A cavity belonging to the ear. 
Vil'ei. [L.] Fine, small fibres. 
Vi'rus. [L., poison.] Foul matter of 

an ulcer; poison. 
Vi'tal. [L. vita, life.] Pertaining to 

life. 
Vit're-otjs. [L. vitrum, glass.] Be- 
longing to glass. A humor of the eye. 
VO'ear. [L. vola, the hollow of the 

hand or foot.] Belonging to the palm 

of the hand. 
Vo'mer. [L., a ploughshare.] One of 

the bones of the nose. 

Zyg-O-mat'i-ctjs. [Gr. $vyoc, zugos, a 
yoke.] A term applied to some mus- 
cles of the face, from their attachment. 



INDEX 



A.9 PAGE. 

Abdomen, 34 

Absorption, 181 

, Varieties of, 183 

, Cutaneous, 185 

Acetabulum, 38 

Acids, Acetic, 28 

, Benzoic, 28 

, Muriatic, 440 

, Nitric, 440 

, Oxalic, 28, 440 

, Sulphuric 440 

Air, Composition of the, 223 

, Influence of, on the Muscles, 90 

, Quality of the, 223,318 

, Quantity inhaled, 222 

, Quantity exhaled, 228 

. , Impure Air, the Effects of, 232 

Air- Vesicles, 212 

Albumen, . 27 

Anima j Heat, 252 

Aorta, 159 

, Valves of the, 157 

Apparatus, 18 

Arteries, Structure of the, 158 

, Cutaneous, 285 

, Pulmonary, 158 

Attitude, Effects of, on Digestion,. 152 

, Effects of, on the Voice. 274 

, Effects of, in Respiration, 245 

Auricles of the Heart, 156 

Asphyxia, from Drowning, 249 

, from Electricity, 250 

, from Hanging, 250 

, from Carbonic Gas, 251 

Azote, 26 

B. 

Bathing, Necessity of, 311 

, Methods of, 313 

. , Proper Time for, 316 

, Influence of, on the Sys- 
tem, 316 

, Frequency of, 317 

Beds, 309 

Bile, 122 

Blood, Composition of, 154 



PAGE. 

Blood, Color of, 204 

, Quantity of, 171 

, Change of, 225 

, Impure, Effects of, 205 

Bones, Anatomy of the, 29 

, Physiology of the, 48 

, Hygiene of the, 53 

of the Head, 32 

of the Trunk, 34 

of the Upper Extremities,... .39 

of the Lower Extremities,. . . .42 

, Composition of, 29 

, Ossification of, 30 

, Union of fractured, 62 

, Influence of Position on the,. .55 

Brain, 329 

, Functions of the, 346 

, Effects of Impure Elood on the, 360 

, Effects of inadequate Mental 

Exertion, 361 

, Effects of excessive Mental 

Exertion, 363 

, Directions for exercising the,. .368 

, Membranes of the, 334 

, Injuries of the, 377 

Bronchia, 212 

Bronchitis, 214 

Burns and Scalds, 319 

Burs^e Mucosa, 46 

C, 

C iECUM, 118 

Capillaries, 163 

Carbon, 26 

Carbonic Gas, where formed, 224 

, Effects of, when 

inhaled, 230 

, Effects of, on Com- 
bustion, 230 

, Effects of, on Respi- 
ration, 231 

Carpus, 41 

Cartilage, 45 

of the Larynx, 269 

Caul, 123 

Cellular Tissue, 19 

Cerebellum, 331 



456 



INDEX. 



PAGE. 

Cerebrum, 330 

Chest, 35 

. Compression of the, 56 

, Influence of the Size of the,. .239 

Chilblains, 321 

Chlorine, 27 

Chyle, 126 

Chyme, 126 

Circulatory Organs, Anatomy,. 151 

Physiology of the.. 164 

Hygiene of the, 172 

Clavicle, 39 

Clothing, Kind of, , 301 

, Amount of, 305 

, Cleanliness of, 308 

Coccyx, 38 

Colds, Treatment of, 248 

Colon, 119 

Consumption, how frequently pro- 
duced, 247 

Corns, Treatment of, 295 

Cuticle, Structure of the, 282 

, Use of the, 293 

Cutis Vera, Structure of the, 283 

I>. 

Definitions, General, 13 

Diaphragm, 73, 215 

Digestive Organs, Anatomy of the, 113 

, Physiology of the,.. 124 

, Hygiene of the, 129 

, Influence of the 

Mind on the, 148 

, Influence of Pure 

Air on the, 151 

, Influence of Posi- 
tion on the,., 152 

Drinks, how taken, 145 

Drowned Persons, Treatment of,. 249 
Duodenum, 117 

E. 

Ear, Bones of, 34, 415 

Epiglottis, 125, 270 

exhalants, 192 

Exercise, how it should be taken, ...91 

, Influence of, on the Bones, 53 

, Influence of, on Muscles,. .85 

— , Influence of, on the Cir- 
culation, 173 

E YE , 394 

Expiration, how effected, 220 



I"» PAGE 

Face, Bones of the, 31 

Fascia, 66 

Fat, 67, 195 

Femur, 42 

Fibre, 18 

Fibrin , 27 

Fibula, 42 

Filament, is 

Flannel, Use of, 302 

Fluids, Use of, 17 

Follicle, 192 

Food, Quantity of the, 129 

, Qualify of the, 134 

, Manner in which it is taken, ..142 

, Condition of the system, 

when taken, 146 

FOOT, Bones of the, 44 

Frozen Limbs, Treatment of,. 320 

O. 

Gastric Juice, 125 

Gelatin, 27 

Glands, 1 93 

, Gastric, , 116 

, Lachrymal, 402 

, Lymphatic, 183 

, Mesenteric, 121 

, Oil, 288 

, Perspiratory, 290 

, Salivary, 114 

Glottis 271 

II. 

Hair, 322 

Heart, 154 

, Auricles of the, 156 

, Ventricles of the, 156 

Heat, Animal, 252 

, Hygiene of, 261 

Hearing, Anatomy of the Organs of, 414 

, Physiology of the Organs 

of, 420 

, Hygiene of the Organs of,. 422 

Humerus, 39 

Hemorrhage, Means of arresting,.. 175 
Hydrogen,.. 26 

I. 

Ileum, 118 

Intestines, 117 

innominatum, 37, 



INDEX. 



457 



PAGE. 

Inspiration, how effected, 219 

Iron, 25 

I. 

Jejunum, 118 

Joints, Structure of the, . .45 

ti. 

Lacteals, 120, 181 

Lamin-e, .*. 17 

Larynx, 2G8 

Laryngitis, 27G 

Ligaments, 23, 47 

, Use of, 50 

, Capsular, 40 

Light, Influence on the Skin, 318 

Lime, 25 

Liver, 122 

Lungs, 209 

Lymph, 30 

Lymphatics, Anatomy of the, 181 

, Physiology of the, 183 

, Hygiene of the, 188 

Cutaneous, 287 

M. 

Magnesia, .25 

Marrow, Uses of, 24 

Mediastine, 211 

Medulla Oblongata, 333 

Me mbrane, 19 

, Adipose, 20 

, Cellular, 19 

, Dermoid, 22, 282 

, Mucous, 21 

5 Muscular,. 24 

, Serous, 21 

Mesentery, 120 

Metacarpus,. 41 

Mouth, Structure of, 113 

Mucus, 23 

Muscles, Anatomy of, C4 

, Physiology of, 76 

, Hygiene of, S5 

, Compression of, 93, 270 

, Exhaustion of, 87, 101 

, Effects of Pure B'.ood on,.. 89 

, Effects of Pure Air on the, .9) 

, Effects of Light on the, 90 

. , Influence of the Mind on,. .93 

, Influence of Position on,.. 96 

39 



Muscles, Intercostal, 216 

■, Respiratory, 21G 

N. 
Nails, 324 

Nerves, Cranial, . . 335, 350 

, Cutaneous, 286 

, Respiratory, 340, 352 

, Spinal, 341, 351 

, Sympathetic, 343, 356 

Nervous System, Anatomy of, 327 

, Physiology of,.. 346 

, Hygiene of, 358 

Nitrogen, 23 

Nose, Structure, 389 

Nurses, Directions for, 433 

Nutrition, 200 

, Hygieu-e of, 205 

0. 

CEsophagus., 116 

Oil-Glands, Structure of the, 288 

, Use of the, 297 

Omentum, 123 

Organ,. . . 18 

Organic and Inorganic Bodies, 

Difference between, 14 

Orifice, Cardiac, 116 

, Pyloric, 116 

o.smazome,. 28 

Oxygen, 26 

, Quantity at each Inspira- 
tion 222 



Papilla, 284 

Pancreas, 122 

Parotid Gland, 114 

Patella, 42 

Pericardium, 155 

Perichondrium, 31 

Pericranium, 31 

Periosteum, 31 

Pelvis, Bones of the, 37 

Perspiratory Apparatus, 290 

Use of,... 298 

Phalanges, 42, 45 

Pharynx, 115 

Phosphorus, 26 

Pleura, 211 

Poisons, and their Antidotes, 439 



458 



INDEX. 



PYGE. 

Potash, 25 

Preservation of Health, 425 

n. 

Radius, 41 

Reading, Proper Position in, 275 

Rectum, 120 

Removal of Disease, 42G 

Respiratory Organs, Anatomy of,209 

, Physiology of,... 217 

, Hygiene of, 228 

Retina, 397 

Ribs, 35 

Rooms, Ventilation of, 233 

, Warming of, 238 

§. 

Sacrum, , 33 

Saliva, its Use, 124 

Scapula, 39 

Secretory Organs, Anatomy of,. 192 

, Physiology of. 193 

, Hygiene of,... 197 

Senses, .; 378 

Sick-Room, Ventilation of, 236 

Sitting, Proper Position in, 99 

Skeleton, 29 

Skin, Anatomy of the, 282 

, Physiology of the, 293 

, Hygiene of the, 301 

Skull, Structure of, 32 

Sleep, Necessity of, 92 

Sleeping-Rooms, Ventilation of,.. 235 
Smell, Anatomy of the Organs of,.. 389 

, Physiology of the Organs of, . .391 

Soda, 25 

Solids, Arrangement of, 17 

Sound, 273 

Spinal Column, Structure of, 3G 

, Curvature of,. . .57, 60 

Cord, 36, 340 

Spleen, 123 

Sprains, 63 

Stammering, how improved, 281 

Sternum, 35 

Stomach, 116 

Sublingual Gland, 115 

Submaxillary Gland, 115 

Sulphur, 26 

Sutures, 33 



PAOT*. 

Synovial Membrane, 46 

Synovia, 49 

System, . 18 

Tarsus, 42 

Taste, Anatomy of the Organs of,.. .384 

, Physiology of '.he Organs of,. .380 

Teeth, Anatomy of the, ..105 

, Physiology of the, 109 

, Hygiene of the, 110 

Tendons, 23, 65 

Thoracic Duct, 120 

Thorax, 35 

Throat, Extraneous Bodies in, 281 

Tibia, 42 

Tissue, 18 

, Adipose, 20 

, Cartilaginous, 23 

, Fibrous, 22 

, Osseous, 23 

, Nervous, 24 

Touch, Sense of, 378 

, Hygiene of the, 379 

Trachea, 212 

HI. 

Ulna, 40 

Uvea, 396 

V. 

Valves of the Heart, 157 

, Use of the, 1G4 

of the Veins, 102 

Veins, 180 

, Cutaneous, 285 

Ventilation, 233 

Ventricles of the Heart, 156 

Vertebra, 36 

Vision, Anatomy of the Organs of,. .394 

, Physiology of the Organs of,.. 404 

, Hygiene of the Organs of,... 410 

Vocal Organs, Anatomy of the,... 268 

, Physiology of the,. .272 

, Hygiene of the, 274 

Vocal Cords, 270 

W. 

Watchers, Directions for, 436 

Wounds, Treatment of, 178 

Writing, Proper Position when, 103 



KEY TO ANATOMICAL OUTLINE PLATES. 



KEY TO ANATOMICAL OUTLINE PLATES. 



SUGGESTIONS TO TEACHERS. 

In using these plates, we would suggest, that the pupil carefully examine 
the illustrating cuts interspersed with, the text, in connection with the 
lesson to be recited. . The similarity between these and the plates will 
enable the pupil to recite, and the teacher to conduct his recitation, from 
the latter. 

Let a pupil show the situation of an organ, or part, on an anatomical 
outline plate, and also give its structure ; while other members of the class 
note all omissions and misstatements. Another pupil may give the use of 
that organ, and if necessary, others may give an extended explanation. 
The third may explain the laws on which the health of the part depends, 
while other members of the class supply what has been omitted. After 
thus presenting the subject in the form of topics, questions may be pro- 
posed promiscuously, from each paragraph, and where examples occur in 
the text, let other analogous ones be given. 

If the physiology and hygiene of a given subject have not been studied, 
confine the recitation to those parts only on which the pupil is prepared. 
When practicable, the three departments should be united ; but this can 
only be done when the chapter on the hygiene has been learned, while 
the physiology can be united with the anatomy, in all chapters upon 
physiology. 

B 
PLATE I. 

A FRONT VIEW OF THE SKELETON. 

Bones of the Head. 7, The sphenoid bone. 8, The frontal bone. 10, The 
parietal bone. 11, The os unguis. 12, The superior maxillary bone, 
(upper jaw.) 13, The nasal bone. 14, The ethmoid bone. 15, The malar 
bone, (cheek-bone.) 16, The vomer. 17, The inferior maxillary bone, 
(the lower jaw.) a, Its body, b, Its ramus, or branch. 18, The teeth. 

Bones of the Trunk. 1,1, The spinal column. 2, The sternum. 3,3, The 
ribs. 4, The sacrum. 5, The innominatum. 

Bones of the Upper Extremities. 19, The clavicle, (collar-bone.) 20, The 



KEY TO ANATOMICAL OUTLINE PLATES. 

scapula, (shoulder-blade.) 21, The humerus. 22, The ulna. 23, The 
radius. 24, 25, 26, 27, 28, 29, 30, 31, The bones of the carpus, (wrist.) 

32, 32, 32, The five bones of the metacarpus, (the palm of the hand.) 

33, 33, 33, The first range of finger-bones. 34, 34, The second range of 
finger-bones. 35, 35, 35, The third range of finger-bones. 

Bones of the Lower Extremities. 36, The femur, (thigh-bone.) 37, The 
patella, (knee-pan.) 38, The tibia, (shin-bone.) 39, The fibula. 40, 40, 
40, The bones of the tarsus, (instep.) 41, 41, The bones of the metatarsus, 
(middle of the foot.) 42, 42, The bones of the toes. 

Articulations. (Left side of the plate.) 

Ligaments of the Trunk. 1, 1, The common spinal ligament. 2, 2, The 
intervertebral ligament, (cartilage between the vertebrae.) 9, 10, 11, 12, Ar- 
ticulations of the ribs with the spinal column. 13, 13, 14, 15, 16, Liga- 
ments that connect the cartilages of the ribs with the sternum. 

Ligaments of the Upper Extremities. 25, The ligament that connects 
the clavicle and sternum. 27, The ligament that connects the upper rib 
and clavicle. 28, 29, 30, Ligaments that connect the clavicle and scapula. 
31, 32, 33, 34, Ligaments of the shoulder-joint. 35, 35, 36, Ligaments of 
the elbow-joint. 37, 38, 39, 40, Ligaments of the wrist. 41, 42, 43, 44, 
Ligaments of the fingers. 

Ligaments of the Lower Extremities. 49, 49, Ligaments of the hip-joint. 
50, 50, Ligaments of the patella. 51, 52, 53, 54, 55, Ligaments of the 
knee-joint. 56, A large bursa mucosa. 57, The ligament of the tibia and 
fibula. 58, 58, The interosseous ligament. 59, 59, Ligaments of the an- 
kle-joint. 60, 61, 62, Ligaments of the metatarsus. 63, 64, Ligaments of 
the toes. 

A, The brachial artery. B, The brachial vein. C, The radial artery. 
D, The femoral artery. E, The femoral vein. F, G, The anterior tibial 
ar tery. 

PLATE II. 

* A BACK VIEW OF THE SKELETON. 

Bones of the Head. 5, The occipital bone. 6, The parietal bone. 7, Tho 
temporal bone. 8, The frontal bone. 9, The sphenoid bone. 15, The 
malar bone. 16, The nasal bone. 17, The superior maxillary bone, (upper 
jaw.) 18, The inferior maxillary bone, (lower jaw.) 19, The teeth. ' 

Bones of the Trunk. 1,1, The spinal column. 2, The sacrum. 3, The 
coccyx. 20, The innominatum. 4, 4, The ribs. 

Bones of the Upper Extremities. 21, The clavicle, (collar-bone.) 22, The 
scapula, (shoulder-blade.) 23, The humerus. 24. The ulna. 25, The 
radius. 26, 27, 28, 29, 30, 31, 32, The bones of the carpus, (wrist.) 
33, 33, 33, The bones of the metacarpus, (palm of the hand.) 34, 34, 34, 
The first range of finger-bones. 35, 35, The second range of finger-bones. 
36, 36, 36, The third range of finger-bones. 



KEY TO ANATOMICAL OUTLINE PLATES. 

Bones of the Lower Extremities. 37, The femur, (thigh-bone.) 38, The 
patella, (knee-pan.) 39, The tibia, (shin-bone.) 40, The fibula. 41, 42, 
43, 44, 45, The bones of the tarsus, (instep.) 46, 46, The bones of the 
metatarsus, (middle of the foot.) 47, 47, Bones of the toes. 

Articulations. (Left side of the plate.) 
Ligaments of the Trunk. 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, Ligaments of the 
spinal column. 14, 14, 15, 15, Ligaments that connect the ribs and spinal 
column. 11, 11, 21, 22, 23, 24, 25, 26, Ligaments that connect the sacrum 
and innominatum. 

Ligaments of the Upper Extremities. 27, 28, Ligaments that connect the 
clavicle and scapula. 29, The capsular ligament of the shoulder-joint. 
30, 30, Ligaments of the elbow. 31, 32, 33, 34, Ligaments of the carpus, 
(wrist.) 

Ligaments of the Loxoer Extremities. 9, Tendon of the gluteus muscle. 
35, The capsular ligament of the hip-joint. 36, 36, Ligaments of the knee- 
joint. 37, The ligament that connects the tibia and fibula. 38, The in- 
terosseous ligament. 39, 40, Ligaments of the ankle-joint. 



PLATE HI. 

A FRONT VIEW OF THE MUSCLES. 

Muscles of the Head and Neck. 7, The sterno-mastoideus muscle. 
8, The sterno-hyoideus muscle. 9, The omo-hyoideus muscle. 10, The 
trapezius muscle. 11, The orbicularis oculi muscle. 12, The frontal 
muscle. 14, The orbicularis oris muscle. 15, The elevator muscle of the 
nostrils. 16, The zygomatic muscle. 17, The depressor of the lower lip. 
18, The depressor anguli oris muscle. 19, The triangular muscle of the 
nose. 20, 21, The aural muscles. 22, The masseter muscle. 

Muscles of the Trunk. 2, 3, The external oblique muscles. 

Muscles of the Upper Extremities. 1, The grand pectoral muscle. 
3, 4, The serratus muscle. 23, The deltoid muscle. 24, The biceps 
brachialis muscle. 25, The coraco-brachialis muscle. 26, The anterior 
brachial muscle. 27, The triceps brachialis muscle. 28, The long su- 
pinator muscle. 29, The external radial muscle. 30, The pronator teres 
muscle. 31, The anterior radial muscle. 32, The palmaris brevis muscle. 
33, The anterior ulnar muscle. 35, The palmar muscle. 36, The abductor 
muscle of the thumb. 37, The adductor muscle of the thumb. 38, 39, 
Small flexor muscles of the thumb. 40, The abductor muscle of the little 
finger. 41, 41, The lumbricales muscles. 61, 61, The bifurcation of the 
tendons of the superficial flexor muscle, in the fingers. 

Muscles of the Lower Extremities. 42, The fascia lata muscle. 43, The 
sartorius muscle. 44, The rectus femoris muscle. 45, The vastus externus 
muscle. 46, The vastus internus muscle. 47, The internal straight muscle. 
48, The pectineus muscle. 49, The adductor muscle. 50, The psoas 



KEY TO ANATOMICAL OUTLINE PLATES. 

muscle 51, The tibialis anticus muscle. 52, The long extensor muscle 
of the great toe. 53, The long extensor muscle of the toes. 54, The 
anterior peroneal muscle. 55, The long lateral peroneal muscle. 56, 57, The 
gastrocnemii muscles. 58, The long flexor muscle of the great toe. 
59, The short extensor muscles of the toes. 60, The abductor muscle of 
the great toe. 

The figures and letters on the left side of the plate, indicate the position 
of important fascise, that cover the muscles and enclose the tendons. 



PLATE IY. 
A BACK VIEW OF THE MUSCLES. 

Muscles of the Head and Neck. 4, The sterno-mastoideus muscle. 
5, The complexus muscle. 6, The mylo-hyoideus muscle. 7, 8, The oc- 
cipito-frontalis muscle. 9, The masseter muscle. 10,11,12, The anterior, 
middle, and posterior aural muscles. 13, The temporal muscle. 

Muscles of the Trunk. 1,1, The trapezius muscle. 2, The latissimus dorsi 
muscle. 3, The- rhomboideus muscle. 4, The external oblique muscle. 

Muscles of mc Tipper Extremities. 5, The deltoid muscle. 6, 7, The 
infra-spinatus muscle. 9, The triceps extensor muscle. 10, The internal 
brachial muscle. 11, The long supinator muscle. 12, The external radi- 
al muscle. 13, The second external radial muscle. 14, The anconeus 
muscle. 15, 16, The extensor digitorum communis muscle. 17, The ex- 
tensor carpi ulnaris muscle. 18, The flexor carpi ulnaris. 19, 20, The 
extensor ossis metacarpi pollicis muscles. 21, An extensor muscle of the 
thumb. 22, 28, Interossii muscles. 

Muscles of the Lower Extremities. 29, The -gluteus maximus muscle. 
30, The gluteus medius muscle. 31, The biceps flexor cruris muscle. 
32, The semi-tendinosus muscle. 33, The semi-membranosis muscle. 
34, The gracilis muscle. 35, The adductor muscle. 36, The vastus ex- 
ternus muscle. . 37, The sartorius muscle. 38, 39, The gastrocnemii 
muscles. 40, The long peroneal muscle. 41, The external peroneal mus- 
cle. 42, The long flexor muscle of the great toe. 43, The long extensor 
muscle of the toes. 44, The short extensor muscle of the toes. 47, The 
short flexor muscle of the toes. 

The figures and letters on the left side of the plate, indicate the position 
of membranous fasciae which envelop the muscles and tendons. 

PLATE V. 

ORGANS OF THE THORAX AND ABDOMEN. 

Fig. 1. The Mouth and Neck. (A Side view.) 1, The upper lip. 2, The 
lower lip. 3, The upper jaw. 4, The lower jaw. 5, The tongue. 6, The 
hard palate, (roof of the mouth.) 7, The parotid gland. 8, The sub- 



KEY TO ANATOMICAL OUTLINE PLATES. 

lingual gland. T, The larynx. 10, The pharynx. 11, The oesophagus. 

12, The upper portion of the spinal column. C, The spinal cord. 

The Chest and its Organs. 9, 9, The trachea. R, The right auricle 
of the heart. L, The left auricle. 13, The left ventricle of the heart. 
14, The right ventricle. 15, The aorta. 16, The pulmonary artery. 
17, The vena cava descendens. 18, The right subclavian vein. 19, The 
left subclavian vein. 29, The right jugular vein. 21, The left jugular 
vein. 22, The right carotid artery. 23, The left carotid artery. 24, 25, 
26, The upper, middle, and lower lobes of the right lung. 27, 28, The 
upper and lower lobes of the left lung. 29, 29, 29, The diaphragm. 
P, P, P, P, The pleura, that lines the cavity of the chest. S, S, The clavi- 
cles. 0, O, O, 0, The ribs. M, M, M, M, Muscles of the chest. 40, The 
thoracic duct, opening into the left subclavian vein. 

The Abdomen and its Organs. 30, The stomach. 31, 32, The right and 
left lobe of the liver. F, The fissure that separates the two lobes. 33, The 
gall bladder. 34, 34, The duodenum. 35, The ascending colon. 36, The 
transverse colon. 37, The descending colon. 38, 38, 38, 38, The small 
intestine. 39, 39, The walls of the abdominal cavity turned down. 41, 
The spleen. 

Fig. 2. The Relation of the Laeteals and Thoracic Duct. 1, 1, A section 
of the small intestine. 2, 2, 2, 2, 2, 2, 2, 2, Mesenteric glands, through 
which the laeteals from the intestine pass. 3, Several lacteal vessels 
entering the enlarged portion and commencement of the thoracic duct. 
5, 5, 5, The thoracic duct. 6, The thoracic duct opening into the left sub- 
clavian vein. 7, (See 40, Fig. 1.) 8, The right subclavian vein. 9, The 
vena cava descendens. 10, 11, 11, The aorta. 12, The carotid arteries. 

13, 13, The jugular veins. 14, The vena azagos. 15, 15, The spinal col- 
umn. 16, The diaphragm. 

Fig. 3. The Relation of the Larynx, Trachea, Bronchia, and Air-cells. 
1, 1, 1, An outline of the right lung. 2, 2, 2, An outline of the left lung. 
3, The larynx. 4, The trachea. 5, The right bronchia. 6, The left bron- 
chia. 7, 7, 7, 7, Divisions of the right bronchia. 8, 8, 8, 8, Divisions of the 
left bronchia. 9, 9, 9, 9, 9, 9, Air-cells. 

Fig. 4. An ideal View of a lateral and vertical Section of the Larynx. 

1, 1, The superior vocal cords, (ligaments.) 2, 2, The inferior vocal cords. 
3, 3, The glottis. 4 ; 4, The ventricles of the larynx. 

PLATE VI. 

HEART, ARTERIES, AND VEINS. 

Fig. 1. The Heart and large Arteries. 1, The right auricle of the heart. 

2, The right ventricle of the heart. 3, The left auricle. 4, The left ven- 
tricle. 5, The pulmonary artery. 6, The aorta. 7, 7, The descending 
aorta. 8, The arteria innominata. 9, The left carotid artery. 10, The left 
subclavian artery. 56, The right subclavian artery. 



KEY TO ANATOMICAL OUTLINE PLATES. 

Arteries of the Neck and Head. 15, The right carotid artery. 16, The 
left carotid artery. 17, The right temporal artery. 50, The right facia] 
artery. 54, The left temporal artery. 

Arteries of the Upper Extremities. 11, 11, The left brachial artery. 
12, The left radial artery. 13, 13, The right brachial artery. 14, The 
right radial artery. 51, The right ulnar artery. 

Arteries of the Lower Extremities. 18, The left iliac artery. 19, The right 
iliac artery. 20, The left femoral artery. 21, The right femoral artery. 
22, The peroneal artery. 23, The left anterior tibial artery. 24, The mus- 
cular artery. 25, 25, The right and left arteria profunda. 26, The right 
anterior tibial artery. 27, The right peroneal artery. 

The Veins of the Neck and Head. 28, The vena cava descendens 
29, The left subclavian vein. 30, The right subclavian vein. 31, The 
right jugular vein. 32, The left jugular vein. 53, The right temporal 
vein. 55, The left temporal vein. 49, The right facial vein. 

Veins of the Upper Extremities. 33, The left brachial vein. 34, The left 
radial vein. 35, The right brachial vein. 36, The right radial vein. 
51, The right ulnar vein. 

Veins of the Lower Extremities. 37, The vena cava ascendens. 38, The 
left iliac vein. 39, The right iliac vein. 40, The left femoral vein. 41, The 
right femoral vein. 42, The left anterior tibial vein. 43, The left per- 
oneal vein. 44, The right anterior tibial vein. 45, The right peroneal 
vein. 46, 46, The profunda veins. 47, The muscular veins. 48, 48, 48, 
48, 48, 48, Intercostal arteries and veins. 

Fig. 2. The Relation of the Cavities of the Heart to the large Blood-vessels. 
1, The vena cava descendens. 2, The vena cava, ascendens. 3, The right 
auricle of the heart. 4, The opening between the right auricle and right 
ventricle. 5, The right ventricle. 6, The tricuspid valves. 7, The pul- 
monary artery. 8, 8, The branches of the pulmonary artery that pass to 
the right and left lung. 9, The semilunar valves of the pulmonary artery. 
10, The left pulmonary veins. 11, The right pulmonary veins. 12, The 
left auricle. 13, The opening between the left auricle and left ventricle. 
14, The left ventricle. 15, The mitral valves. 16, 16, The aorta. 17, The 
semilunar valves of the aorta. 18, The septum between the right and left 
ventricle. 

Fig. 3. An ideal View of the Heart, Arteries, and Veins. A, The right 
auricle. B, The right ventricle. C, The tricuspid valves. D, The open- 
ing between the right auricle and right ventricle. E, The left auricle. 
F, The left ventricle. G, The mitral valves. H, The opening between 
the left auricle and left ventricle. I, The septum between the right and 
left ventricle. K, The pulmonary artery. L, The semilunar valves of the 
pulmonary artery. M, M, The right pulmonary artery. .N, N, The left 
pulmonary artery. O, O, O, O, O, O, The capillary vessels of the lungs. 
P, P, P, The right pulmonary vein. Q, Q, The Left pulmonary vein. 
K, R, The aorta. S, The semilunar valves of the aorta. T, T, A branch 
of the aorta to the upper extremities. U, U, U, U, A branch to the lower 
extremities. V, V, V, V, V, V, The capillary vessels at the extremity 



KEY TO ANATOMICAL OUTLINE PLATES. 

of the branches of the aorta. "W, W, The descending vena cava. 
X, X, X, The ascending vena cava. 

In Figs. 1, 2, 3, the course of the blood through the circulatory vessels 
is indicated by arrows. 

PLATE VII. 
THE PULMONARY CIRCULATION. 

Fig. 1. 1, The right auricle of the heart. 2, The left auricle. 3, The 
right ventricle of the heart. 4, The left ventricle. 5, The pulmonary 
artery. 6, The branch of the pulmonary artery to the left lung. 7, The 
branch of the pulmonary artery to the right lung. 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 
Branches of the pulmonary artery in the right and left lung. 9, 9, 9, 9, 9, 9, 
Air-cells. 10, 10, 10, 10, 10, 10, 10, Small pulmonary veins in the right 
and left lung. 11, The left pulmonary vein. 12, 12, The right pulmonary 
vein. 

Fig. 2. An ideal View of the Pulmonary Circulation. 1, 1, The right 
lung. 2, 2, The left lung. 3, The trachea. 4, 4, 4, 4, 4, The right bronchia. 
5, 5, 5, 5, 5, The left bronchia. 6, 6, 6, 6, 6, 6, Air-cells, with arteries and 
veins passing around them. 7, The right auricle of the heart. 8, The 
right ventricle of the heart. 9, The tricuspid valves. 10, The pulmonary 
artery. 11, 11, 11, 11, The right pulmonary artery. 12, 12, 12, 12, 12, The 
left pulmonary artery. 13, 13, 13, 13, The right pulmonary vein. 

14, 14, 14, 14, The left pulmonary vein. 15, The left auricle. 16, The 
left ventricle. 17, The mitral valves. 18, The septum between the right 
and left ventricles. 

Fig. 3. An ideal View of the Capillaries. 1, 1, A branch of the pul- 
monary artery. 2, 2, A branch of the pulmonary vein. 3, 3, Capillary 
vessels between the artery and vein. 

Fig. 4. An ideal View of the Relations of the Bronchia, Air-cells, Pul- 
monary Arteries, and Veins. 1, A bronchial tube. 2, 2, 2, Air-cells. 
3, A branch of the pulmonary artery. 4, A branch of the pulmonary vein. 



PLATE VIIL 

THE CEREBRUM, CEREBELLUM, SPINAL CORD, AND 
NERVES. 

I, The cerebrum. 2, The cerebellum. 3, 3, The spinal cord. 4, The 
brachial plexus of nerves. 5, The lumbar plexus of nerves. 6, The sa- 
cral plexus of nerves. 7, The facial nerve. 8, 17, The radial nerve. 
9, 9, 16, The ulnar nerve. 10, The median nerve. G, The circumflex 
nerve of the shoulder. 

II, 11, The great sciatic nerve. 12, The external popliteal, or peroneal 



KEY TO ANATOMICAL OUTLINE PLATES. 

nerve. 13, 13, The posterior tibial nerve. 14, The external tibial nerve. 
15, The muscular branch of the external peroneal nerve. 18, The muscu- 
lar branch of the sciatic nerve. P, Q, The posterior tibial nerve. 

The letters and other figures indicate minor nervous filaments dis- 
tributed to the various muscles and the skin. 



PLATE IX. 

THE SKIN. 

Fig. 1. A perspiratory Tube and Gland. 1, 1, The contorted portion of 
;he tube that forms the gland. 2, 2, Two branches which unite to form 
ihe main duct of the gland. 3, 3, The perspiratory tube. 4, The cuticle. 
9, Its colored portion. 6, The cutis vera, (true skin.) 7, 7, Fat vesicles, 
in which the gland is imbedded. 

Fig. 2. A Papilla of the Skin. 1, 1, Two papillae, formed of an artery, 
vein, and nerve. 2, 2, 2, 2, Nerves forming a loop in the papillae. 3, 3, Ar- 
teries of the papillae. 4, 4, Veins of the papillae. 5, 5, A net-work of 
arteries, veins, and nerves. 6, 6, Nerves of the skin. 8, 8, Arteries of 
the skin. 7, 7, Veins of the skin. 

Fig. 3. A Hair, audits Oil-Glands. 1, 1, The hair. 2, 2, The sheath 
of the hair. 3, Oil-glands that surround the bulb of the hair, the ducts of 
which open into the sheath of the hair, (2, 2.) 

Fig. 4. A Section of the Skin. 1,1, The cuticle. 2, 2, Its colored por- 
tion. 3, 3, The papillary layer. 4, 4, A net-work of arteries, veins, and 
nerves, upon the upper surface of the cutis vera. 5, 5, 5, 5, The cutis 
vera, (true skin.) 6, 6, 6, Hairs that originate in the cutis vera. 7, 7, 7, Oil- 
glands, the ducts of which connect with the sheath of the hair. 8, 8, 8 8, 
8, 8, 8, 8, Perspiratory glands and their ducts. 9, 9, 9, 9, 9, Nerves of the 
skin. 10, 10, 10, 10, 10, Arteries of the skin. 11, 11, 11, 11, 11, Veins of 
the skin. 12, 12, 12, 12. Papillae, or ridges of the skin. 



PLATE X. 
AN ANTERO-POSTERIOE, SECTION OF THE EYE. 

Fig. 1. 1, 1, The sclerotic coat. 2, 2, The cornea. 3, 3, The choroid 
coat. 4, 4, The retina. 5, 5, The iris. 6, 6, The posterior chamber of 
the eye that contains the aqueous humor. 7, 7, The anterior chamber. 
8, 8, The pupil. 9, The crystalline humor. 10, 10, The vitreous humor. 
11, The optic nerve. 12, A representation of a pen. 13, An inverted 
image of the pen (12) on the retina. 14, 14, A canal surrounding the 
crystalline humor. 15, 15, The bevelled junction of the cornea and scle- 



KEY TO ANATOMICAL OUTLINE PLATES. 

rotic coats. A, a perpendicular ray of light from the pen. B, B, oblique 
rays, that are refracted in passing through the humors of the eye. 

Fig. 2. A View of the External, Middle, and Internal Ear. 1, 1, The ex 
ternal ear. 2, The meatus auditorius externus, fthe tube that connects 
with the middle ear.) 3, The membrana tympani, (drum of the ear.) 
8, 8, The tympanum, (middle ear.) 4, The malleus. 5, The incus. 
6, The orbicularis. 7, The stapes, (stirrup-bone,) that connects with the 
vestibule of the internal ear. 9, 9, (4, 5, 6, 7, The small bones of the mid- 
dle ear,) 10, 11, 12, The semicircular canals. 13, 13, The cochlea. 
14, The auditory nerve. 15, The division of the auditory nerve to the 
semicircular canals. 16, The division to the cochlea. 17, 17 5 The 
Eustachian tube. 18, The chorda tympani nerve. 19, The seventh pair 
(facial) nerve. 20, The styloid process of the temporal bone. 21, 21, 
21, 21, 21, The petrous or hard portion of the tempc<ral bone, in which 
the parts of the middle and internal ear are situated. 



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